This seems to be true even though Pearl Izumi says they are all the same "form fit." I rode the Elite bibs (medium) yesterday but they were so tight in my (not huge) legs I felt like I was pedaling against a resistance band. I will be exchanging them for large Elite bibs. My PI Attack shorts in large feel kind of loose which is why I went with medium bibs.

The medium Pro shorts I received tore the leg gripper the first time I tried them on. Seems like a weak link. So I'll be exchanging those for Elite bibs which double over a piece of fabric at the leg gripper so there's no exposed edge. The chamois in both seems to be very similar and are VERY comfortable.