Patrick, thanks for sharing your experience!

Speed measures are always tricky; usually people just take the time it needs to solve a standard problem as a reference. If your projects don't employ many elements of such standard problems, perhaps there is no speed increase...

I agree with your point about the missing bridge between C++ and Python! Whoever builds a fully automatic translator from Python to C++ code (I'm talking to the NLP programmers here!) is going to be a rich person :)