This wheel size speedometer calculator should answer your questions.
Performance Probe
And the RE-11's really are that good. Good in the wet, good in the dry, and spectacular on the track. They ride better then the RE050A's and have a better tread wear rating (180 vs. 140 for what that's worth)The RE-11's reputation is not based on forum/blog lore, but on actual results at autocross/track events.
Check out the most recent edition of GrassRootsMotorsports magazine. What tire did they choose for their BMW 335i?