Thanks to everyone for the insights. As a Shimano diehard and having built several road, MTB, CX and tandems w/the stuff, I was real curious how SRAM stuff holds up. Has anyone tried running Ultegra shifters with Force or Rival F&R derailleurs and cassette? is this a stupid question?? :-) I have a nice Ultegra shifter set I'd like to use on a new CX build I'm doing - and I'm thinking about SRAM for the rest of it.
To the best of my knowledge I do not think that Shimano shifters will work with Sram derailluers, there is the whole issue of cable pull ratios. However the same was said about Shimano and Campy and as history has shown (see issue 1 of the print mag) this has been busted. Give it time I'm sure someone will post a way to do it. If not you could always look online for killer deals on rival shifters. As to the durability i am a clydesdale and switched from Shimano to Sram four years ago on my road bike and cross bike, great product and they have top notch customer service.
Thanks for the prompt reply Jesse. That's what I suspected (re: compatibility), and further research this weekend confirmed it. I've already started phasing in SRAM cassettes & chains to my bike builds; complete drivetrains are next!