MY XT RD stuff shifts smooth as butter. I did upgrade the casette to XTR to save weight at the last replacement, but no performance differences. I always use XTR/durace chains cuz there isn't much price diff on sale, but I do prefer the shimano chains to the sram. The calulations I ran on my 50/34 suggested I could get away with a medium cage RD, but only if I gave up my 11/34 to an 11/32 and I really wanted that 34 tooth ring paired with my compact double. But on your triple I think you must use the long cage RD. But it shifts very smoothly, no diff. from my ultegra RD did on an 11/27.