I see improvements vs 0.5.0, but no benchmarks to compare it to CPython. I assume this means it compares unfavorably.

They're aiming to speed up Dropbox's workloads, which is a different focus than PyPy, but they could be more open with how they compare.

Here's PyPy's benchmark performance page: http://speed.pypy.org/

Edit: Pyston has a speed page, but it's missing too much data to make a comparison. :( http://speed.pyston.org/comparison/