paxCompiler is actually compiled native code so it will most likely be faster overall than any interpreted scripting engine (the ones I've tested, including PaxScript). This alone is worth it (at least to me). Now in general the compiled scripts (at the present time) will be about 3 times slower than optimized compiled Delphi code. I'm sure this will improve over time too. I've been working with paxCompiler for a while now and I can highly recommend it. So for I've not seen any substantial differences in speed in my test cases. All in all it's a win/win for me (how often does that happen ).

Remember too that it's supports most of the Delphi language syntax and features such as classes, inheritance and more. Like I said, uScroll.pas can be compiled in both with no code changes. That's really impressive in my opinion. You can compile/customize on the fly in the same language that you use everyday.

As for Python, I've looked at it but never tried to use it. For me it's a lot easier to use the same syntax of my main development language. If you can also get great interop between them that's even better.