diff --git a/eeschema/sim/sim_model.cpp b/eeschema/sim/sim_model.cpp
index 14157495e5..0c3cbf80a1 100644
--- a/eeschema/sim/sim_model.cpp
+++ b/eeschema/sim/sim_model.cpp
@@ -794,11 +794,9 @@ bool SIM_MODEL::PARAM::INFO::Matches( const std::string& aParamName ) const
 
 int SIM_MODEL::doFindParam( const std::string& aParamName ) const
 {
-    std::vector<std::reference_wrapper<const PARAM>> params = GetParams();
-
-    for( int ii = 0; ii < (int) params.size(); ++ii )
+    for( int ii = 0; ii < (int) GetParamCount(); ++ii )
     {
-        if( params[ii].get().Matches( aParamName ) )
+        if( GetParam( ii ).Matches( aParamName ) )
             return ii;
     }
 
@@ -814,17 +812,6 @@ const SIM_MODEL::PARAM* SIM_MODEL::FindParam( const std::string& aParamName ) co
 }
 
 
-std::vector<std::reference_wrapper<const SIM_MODEL::PARAM>> SIM_MODEL::GetParams() const
-{
-    std::vector<std::reference_wrapper<const PARAM>> params;
-
-    for( int i = 0; i < GetParamCount(); ++i )
-        params.emplace_back( GetParam( i ) );
-
-    return params;
-}
-
-
 const SIM_MODEL::PARAM& SIM_MODEL::GetParamOverride( unsigned aParamIndex ) const
 {
     return m_params.at( aParamIndex );
diff --git a/eeschema/sim/sim_model.h b/eeschema/sim/sim_model.h
index 2642dd6c05..5615847b36 100644
--- a/eeschema/sim/sim_model.h
+++ b/eeschema/sim/sim_model.h
@@ -485,8 +485,6 @@ public:
 
     const PARAM* FindParam( const std::string& aParamName ) const;
 
-    std::vector<std::reference_wrapper<const PARAM>> GetParams() const;
-
     const PARAM& GetParamOverride( unsigned aParamIndex ) const; // Return the actual parameter.
     const PARAM& GetBaseParam( unsigned aParamIndex ) const; // Always return base parameter if it exists.
 
diff --git a/eeschema/sim/sim_model_ibis.cpp b/eeschema/sim/sim_model_ibis.cpp
index 63d7b5d4b3..7e45c1c949 100644
--- a/eeschema/sim/sim_model_ibis.cpp
+++ b/eeschema/sim/sim_model_ibis.cpp
@@ -40,13 +40,6 @@ std::string SPICE_GENERATOR_IBIS::ModelLine( const SPICE_ITEM& aItem ) const
     return "";
 }
 
-std::vector<std::reference_wrapper<const SIM_MODEL::PARAM>> SPICE_GENERATOR_IBIS::GetInstanceParams() const
-{
-    std::vector<std::reference_wrapper<const SIM_MODEL::PARAM>> vec;
-    return vec;
-}
-
-
 std::vector<std::string> SPICE_GENERATOR_IBIS::CurrentNames( const SPICE_ITEM& aItem ) const
 {
     std::vector<std::string> currentNames;
@@ -278,9 +271,9 @@ SIM_MODEL_IBIS::SIM_MODEL_IBIS( TYPE aType, const SIM_MODEL_IBIS& aSource ) :
 {
     for( PARAM& param1 : m_params )
     {
-        for( auto& param2refwrap : aSource.GetParams() )
+        for( int ii = 0; ii < aSource.GetParamCount(); ++ii )
         {
-            const PARAM& param2 = param2refwrap.get();
+            const PARAM& param2 = aSource.GetParam( ii );
 
             if( param1.info.name == param2.info.name )
                 param1.value = param2.value;
diff --git a/eeschema/sim/sim_model_ibis.h b/eeschema/sim/sim_model_ibis.h
index e35d5a004a..eb70708a5f 100644
--- a/eeschema/sim/sim_model_ibis.h
+++ b/eeschema/sim/sim_model_ibis.h
@@ -44,9 +44,6 @@ public:
 
     std::string IbisDevice( const SPICE_ITEM& aItem, const PROJECT& aProject,
                             const wxString& aCacheDir, REPORTER& aReporter ) const;
-
-protected:
-    std::vector<std::reference_wrapper<const SIM_MODEL::PARAM>> GetInstanceParams() const override;
 };
 
 class SIM_MODEL_IBIS : public SIM_MODEL
diff --git a/eeschema/sim/sim_model_l_mutual.cpp b/eeschema/sim/sim_model_l_mutual.cpp
index 3b693b1025..f460a286ca 100644
--- a/eeschema/sim/sim_model_l_mutual.cpp
+++ b/eeschema/sim/sim_model_l_mutual.cpp
@@ -29,8 +29,15 @@ std::string SPICE_GENERATOR_L_MUTUAL::ItemParams() const
 {
     std::string result;
 
-    for( const SIM_MODEL::PARAM& param : GetInstanceParams() )
+    for( int ii = 0; ii < m_model.GetParamCount(); ++ii )
+    {
+        const SIM_MODEL::PARAM& param = m_model.GetParam( ii );
+
+        if( !param.info.isSpiceInstanceParam )
+            continue;
+
         result.append( " " + SIM_VALUE::ToSpice( param.value ) );
+    }
 
     return result;
 }
diff --git a/eeschema/sim/sim_model_ngspice.cpp b/eeschema/sim/sim_model_ngspice.cpp
index 19a5af27fd..1c57689db1 100644
--- a/eeschema/sim/sim_model_ngspice.cpp
+++ b/eeschema/sim/sim_model_ngspice.cpp
@@ -85,11 +85,9 @@ int SIM_MODEL_NGSPICE::doFindParam( const std::string& aParamName ) const
 {
     // Special case to allow escaped model parameters (suffixed with "_")
 
-    std::vector<std::reference_wrapper<const PARAM>> params = GetParams();
-
-    for( int ii = 0; ii < (int) params.size(); ++ii )
+    for( int ii = 0; ii < (int) GetParamCount(); ++ii )
     {
-        const PARAM& param = params[ii];
+        const PARAM& param = GetParam( ii );
 
         if( param.Matches( aParamName ) || param.Matches( aParamName + "_" ) )
             return ii;
@@ -111,16 +109,29 @@ void SIM_MODEL_NGSPICE::SetParamFromSpiceCode( const std::string& aParamName,
     // First we try to use the name as is. Note that you can't set instance parameters from this
     // function, it's for ".model" cards, not for instantiations.
 
-    std::vector<std::reference_wrapper<const PARAM>> params = GetParams();
-
-    for( int ii = 0; ii < (int) params.size(); ++ii )
+    for( int ii = 0; ii < (int) GetParamCount(); ++ii )
     {
-        const PARAM& param = params[ii];
+        const PARAM& param = GetParam(ii);
 
         if( param.info.isSpiceInstanceParam || param.info.category == PARAM::CATEGORY::SUPERFLUOUS )
             continue;
 
-        if( param.Matches( aParamName ) || param.Matches( aParamName + "_" ) )
+        if( param.Matches( aParamName ) )
+        {
+            SetParamValue( ii, aValue, aNotation );
+            return;
+        }
+    }
+
+    for( int ii = 0; ii < (int) GetParamCount(); ++ii )
+    {
+        const PARAM& param = GetParam(ii);
+
+        if( param.info.isSpiceInstanceParam || param.info.category == PARAM::CATEGORY::SUPERFLUOUS )
+            continue;
+
+        if( param.info.name.ends_with( "_" )
+                &&  boost::iequals( param.info.name, aParamName + "_" ) )
         {
             SetParamValue( ii, aValue, aNotation );
             return;
@@ -138,9 +149,9 @@ void SIM_MODEL_NGSPICE::SetParamFromSpiceCode( const std::string& aParamName,
         {
             // Find an actual parameter with the same id.  Even if the ngspiceParam was
             // superfluous, its alias target might not be.
-            for( int ii = 0; ii < (int) params.size(); ++ii )
+            for( int ii = 0; ii < (int) GetParamCount(); ++ii )
             {
-                const PARAM::INFO& paramInfo = params[ii].get().info;
+                const PARAM::INFO& paramInfo = GetParam( ii ).info;
 
                 if( paramInfo.category == PARAM::CATEGORY::SUPERFLUOUS )
                     continue;
diff --git a/eeschema/sim/sim_model_raw_spice.cpp b/eeschema/sim/sim_model_raw_spice.cpp
index c504f12315..a15935cf13 100644
--- a/eeschema/sim/sim_model_raw_spice.cpp
+++ b/eeschema/sim/sim_model_raw_spice.cpp
@@ -101,8 +101,13 @@ std::string SPICE_GENERATOR_RAW_SPICE::ItemParams() const
 {
     std::string result;
 
-    for( const SIM_MODEL::PARAM& param : GetInstanceParams() )
+    for( int ii = 0; ii < m_model.GetParamCount(); ++ii )
     {
+        const SIM_MODEL::PARAM& param = m_model.GetParam( ii );
+
+        if( !param.info.isSpiceInstanceParam )
+            continue;
+
         if( param.info.name == "model" )
             result.append( " " + SIM_VALUE::ToSpice( param.value ) );
     }
diff --git a/eeschema/sim/sim_model_source.cpp b/eeschema/sim/sim_model_source.cpp
index 3080c649d6..b0b7496532 100644
--- a/eeschema/sim/sim_model_source.cpp
+++ b/eeschema/sim/sim_model_source.cpp
@@ -175,8 +175,10 @@ std::string SPICE_GENERATOR_SOURCE::ItemLine( const SPICE_ITEM& aItem ) const
             break;
 
         default:
-            for( const SIM_MODEL::PARAM& param : m_model.GetParams() )
+            for( int ii = 0; ii < m_model.GetParamCount(); ++ii )
             {
+                const SIM_MODEL::PARAM& param = m_model.GetParam( ii );
+
                 if( ac != "" && ( param.Matches( "ac" ) || param.Matches( "ph" ) ) )
                     continue;
 
diff --git a/eeschema/sim/sim_model_spice_fallback.cpp b/eeschema/sim/sim_model_spice_fallback.cpp
index 320a44d99e..8b8be5734b 100644
--- a/eeschema/sim/sim_model_spice_fallback.cpp
+++ b/eeschema/sim/sim_model_spice_fallback.cpp
@@ -31,8 +31,8 @@ SIM_MODEL_SPICE_FALLBACK::SIM_MODEL_SPICE_FALLBACK( TYPE aType, const std::strin
     // Create the model we *should* have had to copy its parameter list
     std::unique_ptr<SIM_MODEL> model = SIM_MODEL::Create( aType );
 
-    for( const SIM_MODEL::PARAM& param : model->GetParams() )
-        AddParam( param.info );
+    for( int ii = 0; ii < GetParamCount(); ++ii )
+        AddParam( GetParam( ii ).info );
 
     m_spiceCode = aRawSpiceCode;
 }
@@ -66,11 +66,9 @@ int SIM_MODEL_SPICE_FALLBACK::doFindParam( const std::string& aParamName ) const
 {
     // Special case to allow escaped model parameters (suffixed with "_")
 
-    std::vector<std::reference_wrapper<const PARAM>> params = GetParams();
-
-    for( int ii = 0; ii < (int) params.size(); ++ii )
+    for( int ii = 0; ii < GetParamCount(); ++ii )
     {
-        const PARAM& param = params[ii];
+        const SIM_MODEL::PARAM& param = GetParam( ii );
 
         if( param.Matches( aParamName ) || param.Matches( aParamName + "_" ) )
             return ii;
diff --git a/eeschema/sim/sim_model_subckt.cpp b/eeschema/sim/sim_model_subckt.cpp
index 68be2da010..9828e11512 100644
--- a/eeschema/sim/sim_model_subckt.cpp
+++ b/eeschema/sim/sim_model_subckt.cpp
@@ -151,8 +151,8 @@ void SIM_MODEL_SUBCKT::SetBaseModel( const SIM_MODEL& aBaseModel )
         AddPin( pin );
 
     // Same for parameters.
-    for( const PARAM& param : GetBaseModel()->GetParams() )
-        AddParam( param.info );
+    for( int ii = 0; ii < GetBaseModel()->GetParamCount(); ++ii )
+        AddParam( GetBaseModel()->GetParam( ii ).info );
 }
 
 
diff --git a/eeschema/sim/sim_model_switch.cpp b/eeschema/sim/sim_model_switch.cpp
index f02dfe73b8..83bb78c59b 100644
--- a/eeschema/sim/sim_model_switch.cpp
+++ b/eeschema/sim/sim_model_switch.cpp
@@ -66,8 +66,13 @@ std::string SPICE_GENERATOR_SWITCH::ItemParams() const
 {
     std::string result;
 
-    for( const SIM_MODEL::PARAM& param : GetInstanceParams() )
+    for( int ii = 0; ii < m_model.GetParamCount(); ++ii )
     {
+        const SIM_MODEL::PARAM& param = m_model.GetParam( ii );
+
+        if( !param.info.isSpiceInstanceParam )
+            continue;
+
         // The only instance param is "ic", which is positional.
         std::string value = param.value;
 
diff --git a/eeschema/sim/sim_value.cpp b/eeschema/sim/sim_value.cpp
index 7dc2350360..e80fcec8b8 100644
--- a/eeschema/sim/sim_value.cpp
+++ b/eeschema/sim/sim_value.cpp
@@ -29,6 +29,7 @@
 #include <pegtl/contrib/parse_tree.hpp>
 #include <fmt/core.h>
 #include <math/util.h>
+#include <wx/regex.h>
 
 
 #define CALL_INSTANCE( ValueType, Notation, func, ... )                  \
@@ -370,6 +371,13 @@ std::string SIM_VALUE::ConvertNotation( const std::string& aString, NOTATION aFr
                                         NOTATION aToNotation )
 {
     wxString buf( aString );
+
+    // PEGTL is slow as shit.  Avoid if possible.
+    static const wxRegEx plainNumber( wxS( "^[0-9.]*$" ) );
+
+    if( plainNumber.Matches( buf ) )
+        return aString;
+
     buf.Replace( ',', '.' );
 
     SIM_VALUE_PARSER::PARSE_RESULT parseResult = SIM_VALUE_PARSER::Parse( buf.ToStdString(),
diff --git a/eeschema/sim/spice_generator.cpp b/eeschema/sim/spice_generator.cpp
index 68d3e51413..8f796335ad 100644
--- a/eeschema/sim/spice_generator.cpp
+++ b/eeschema/sim/spice_generator.cpp
@@ -62,8 +62,10 @@ std::string SPICE_GENERATOR::ModelLine( const SPICE_ITEM& aItem ) const
 
     result.append( "\n" );
 
-    for( const SIM_MODEL::PARAM& param : m_model.GetParams() )
+    for( int ii = 0; ii < m_model.GetParamCount(); ++ii )
     {
+        const SIM_MODEL::PARAM& param = m_model.GetParam( ii );
+
         if( param.info.isSpiceInstanceParam )
             continue;
 
@@ -181,8 +183,13 @@ std::string SPICE_GENERATOR::ItemParams() const
 {
     std::string result;
 
-    for( const SIM_MODEL::PARAM& param : GetInstanceParams() )
+    for( int ii = 0; ii < m_model.GetParamCount(); ++ii )
     {
+        const SIM_MODEL::PARAM& param = m_model.GetParam( ii );
+
+        if( !param.info.isSpiceInstanceParam )
+            continue;
+
         std::string name = param.info.spiceInstanceName.empty() ? param.info.name
                                                                 : param.info.spiceInstanceName;
         std::string value = SIM_VALUE::ToSpice( param.value );
@@ -230,17 +237,3 @@ std::string SPICE_GENERATOR::Preview( const SPICE_ITEM& aItem ) const
 }
 
 
-std::vector<std::reference_wrapper<const SIM_MODEL::PARAM>> SPICE_GENERATOR::GetInstanceParams() const
-{
-    std::vector<std::reference_wrapper<const SIM_MODEL::PARAM>> instanceParams;
-
-    for( const SIM_MODEL::PARAM& param : m_model.GetParams() )
-    {
-        if( param.info.isSpiceInstanceParam )
-            instanceParams.emplace_back( param );
-    }
-
-    return instanceParams;
-}
-
-
diff --git a/eeschema/sim/spice_generator.h b/eeschema/sim/spice_generator.h
index 8062f50d39..541075e78a 100644
--- a/eeschema/sim/spice_generator.h
+++ b/eeschema/sim/spice_generator.h
@@ -70,8 +70,6 @@ protected:
         return m_model.GetPins();
     }
 
-    virtual std::vector<std::reference_wrapper<const SIM_MODEL::PARAM>> GetInstanceParams() const;
-
     const SIM_MODEL& m_model;
 };
 
diff --git a/eeschema/sim/spice_model_parser.cpp b/eeschema/sim/spice_model_parser.cpp
index 8280bb04f0..fbd244779e 100644
--- a/eeschema/sim/spice_model_parser.cpp
+++ b/eeschema/sim/spice_model_parser.cpp
@@ -292,9 +292,6 @@ SIM_MODEL::TYPE SPICE_MODEL_PARSER::ReadTypeFromSpiceStrings( const std::string&
     for( SIM_MODEL::TYPE candidate : SIM_MODEL::TYPE_ITERATOR() )
     {
         wxString candidate_type = SIM_MODEL::SpiceInfo( candidate ).modelType;
-        wxString candidate_level = SIM_MODEL::SpiceInfo( candidate ).level;
-        wxString candidate_version = SIM_MODEL::SpiceInfo( candidate ).version;
-        bool     candidate_isDefaultLevel = SIM_MODEL::SpiceInfo( candidate ).isDefaultLevel;
 
         if( candidate_type.IsEmpty() )
             continue;
@@ -308,16 +305,16 @@ SIM_MODEL::TYPE SPICE_MODEL_PARSER::ReadTypeFromSpiceStrings( const std::string&
         }
         else if( input_type.StartsWith( candidate_type ) )
         {
-            if( candidate_version != aVersion )
+            if( SIM_MODEL::SpiceInfo( candidate ).version != aVersion )
                 continue;
 
-            if( candidate_level == input_level )
+            if( SIM_MODEL::SpiceInfo( candidate ).level == input_level )
                 return candidate;
 
             if( aSkipDefaultLevel )
                 continue;
 
-            if( candidate_isDefaultLevel && aLevel == "" )
+            if( SIM_MODEL::SpiceInfo( candidate ).isDefaultLevel && aLevel == "" )
                 return candidate;
         }
     }