I wrote a benchmark for Opus audio decoding, as I found that Rev A was too slow for real time playback, while Rev B was just barely fast enough, and I wanted precise performance numbers. I posted more details along with source code and download links for the benchmark in a new thread, but here are the results:
(Rev A: 0.84x, Rev B w/ crank sampling: 1.13x, Rev B w/o crank sampling: 1.24x)
Rev B without crank sampling is nearly 50% faster than Rev A. Rev A and Rev B are supposed to have roughly equivalent performance, but that's clearly not the case with all workloads.
From the thread (rev A was 84% real time and runs at 168 MHz):