As much as this was informative... "However these people often don’t mention that the GIL makes single threaded programs faster" <- how did they ever get that idea?
@jessenoller has a great summary of concurrency in Python: http://jessenoller.com/2009/02/01/python-threads-and-the-glo...
The two worlds seem very similar.
The speed can be sorted as (in most cases): single-threaded code, single-threaded with GIL, single-threaded with fine locks.