Enough with the Cython nonsense! Cython has excellent marketing but it is a really naive compiler. Just figure out how to translate Cython to ctypes+Python for backwards compatibility and use pypy.
Cython is supposed to be a naive compiler, it's primary use-case is for speeding up specific functions by having them compiled. That it uses a python-like language to do this is great.
I'm reasonably certain the C parts of numpy rely more on implementation optimisations than compiler optimisations for their increased efficiency.
You don't know what you're talking about. Using something like Cython (I'm still using Pyrex) to make C extensions dramatically speeds development, if only because it largely solves the reference count problem.
