Originally Posted by OneTinSloth

here is something no one has mentioned about SRAM rear derailleurs. the X9 and X0 RDs use little plastic inserts, pressed into the metal derailleur body that the limit screws thread into. we had a guy who bought a brand new bike from one of our stores, and on his first ride the insert for the high limit screw got pushed out of the derailleur body, which caused his derailleur to shift into the spokes, and his chain to actually get wedged between the cassette and hub flange so tightly that we had to pull his cassette off to get the chain out. this was an X.0 RD, and shouldn't have happened.

SRAM claims they use the plastic inserts so if you cross-thread the limit screws, you just replace the insert and not the whole RD. my argument to that is "who the hell takes their limit screws all the way out anyway?" it almost makes sense, but not enough to justify spending 3 times as much for an X.0 as you would for an XT.

FWIW, i run X.9 shifters and RD on my bike and i love the way the SRAM stuff works (two thumb buttons). i'll probably upgrade to X.0 shifters at some point, for the extra adjustability. i also have run XT with deore pods and honestly, the "crispness" of the shifting is pretty much equal in my eyes.