Hi Peter - I think you're right, and that's another plus for YC. Getting a class together of 40+ startups, you're bound to meet like-minded startups to form your "peer-review" clique (if that's what happens).

In Chicago, we've experienced difficulty in finding other startups who would be interested in forming an accountability group with us, just because our location isn't really "startup rich" (compared to NYC or the Bay Area).

I think once you've found your group, then you should be set, of course, assuming all participants buy the concept.