Well I just swapped back from my 50mm deep carbon wheels to my nothing special fulcrum alum wheels and the only difference I noticed was I wasn't getting blown all over the road in the wind anymore, it was a windy day too. I cracked my rear carbon wheel was the reason for the swap. If I ever buy another set of carbon wheels for the road bike they will be 30mm and no deeper. I'm not fast enough for the DEEP to matter so the only real benefit was they looked cool.