I also have XT on my Giant and it's been pretty good stuff...but, I only have about 15,000 miles on components and bike, and the last 5,000 miles has been on a trainer. But the shifters tend to go out of adjustment frequently so I'm always having to do something to get them to work again. This is an older generation so maybe those had bugs. Odd bike, the thing came with all XT stuff except the wheels and hubs which were cheap and on the heavy side from China!