I decided to wait a few months before reviewing mine so I'd have enough rides to draw some conclusions. I have the 2011 model, size S. Contrary to what others have been saying, I actually found these to fit a bit large. I have two other pairs of PI shorts, both of which fit tighter.

Overall, I really like the bib. It's comfortable, the drop tail stays in place, and making pit stops is easy (just be sure to hold the shorts forward so that they don't touch the toilet). The only two things I dislike: (1) The plasticky leg grippers are a bit uncomfortable off the bike (I don't notice them when riding, though). (2) The straps don't stay centered across my chest -- sometimes I wind up with them off to the side and the buckle somewhere over one breast. It doesn't usually affect comfort and is easily adjusted, but it's another one of those factors that makes the bib seem looser than its stated size.