i have never had xt hubs
but
i have 105 hubs on my road bike
which are one quality level down from xt
and they have survived since 1992
ridden in all weather
had the freehub body replaced three times
once because the original failed
once to convert to 8 speed from seven
and once to convert back to 7 speed

in 1997 or so
I repacked the bearings in the rear hub
but the cones were pitted and I could not immediately find the exact replacements
and so i used some generic aftermarket ones
which worked fine
but did not fit the labyrinth seals
and so you can see the bearings twirling around if you look in the end

and i have ridden on those hubs for another few thousand kms after that
all weather and all terrain
with me never weighing less than 250 lbs
and a second frame just broke using these hubs
and I will soon have them mounted on a third frame

in short
my shimano hubs are the oldest and most reliable piece of equipment on any bicycle i own