I have a friend who tried the SRAM groupset this season on his Seven (he's CAT1 and sponsored by Seven this season) but he switched back to Dura-Ace because he couldn't get used to the shifting and it was costing him time during races.

Personally, I haven't tried it but just thought I'd throw that out there for anyone who's interested.

BTW-I'm riding Campy on both my bikes. I like the thumbshifters and the fact that you can go up or down one, two or three gears at a time with one flick of the shift lever. I can even operate the thumbshift while in the drops. I had Ultegra on another bike but traded it with a friend of mine last year for some parts he had from another bike and a used frameset. I had about 1200 miles on the Ultegra and I have a few thousand miles on my Campy bikes now.