In order of preference - Assos Mille S5, PI Pro's, and Performance Ultra's. I never believed the hype on Assos, then was looking at one of the overseas cycling retailers (Chain Reaction) about 1 1/2 yrs ago and they had a great sale on the Mille's. I bought a pair, and yes it DOES make a difference. They are my "go to" bibs for the more technical and difficult rides with lots of vertical and / or distance. The flatter pad does a better job of cushioning me bum, reducing sore spots, and not irritating those "extra" folds of skin left over from former tub o' goo days. PI's are also very comfortable, and I use the Performance Ultra's for training, shorter distance and flatter events.

You can be sure I'll be wearing the Assos on the Death Ride in July. I'd try to buy the Assos bibs when on sale (now have 2 pair), but I guarantee your bottom will think you're the "top" if you do!