I'm a SRAM fan. I don't have experience with the Red grouppo, I've got Force on my Guru, and Rival on the Litespeed.

My biggest issue has been with the Force setup, it's had some problems. My Force group was 1st generation, so perhaps I set myself up as a guinea pig for some kinks being worked out. I had a front shifter that had a "sticky" return spring, and a front dérailleur that I sheared off the inside cage plate on (and trust me, I'm not THAT strong). That being said, my LBS spoke to SRAM and they replaced both parts free of charge, and replacements have worked flawlessly.

The Rival components have been completely bullet proof, no issues what so ever. Once you get used to the shifting change from Shimano or Campy, I think you'll prefer the setup. The components on both are quiet, braking is good, with the feel and application more "linear", not at all grabby. Shifts are confirmed with a more mechanical click in than Shimano, that's personal preference. Just my $.02.