None actually..
I had the 3rd/4th gear cluster replaced to fix a crunchy syncro, and the current failure isn't the gearset at all..
a circlip that retains the centre diff has come askew and gone through the feed gears for the output shaft, taking the corner off two teeth on the output shaft gear, and ten or more corner off the feed gear..
the gearset itself has no missing teeth, just semi sad syncro's, oh and a loose nut on the end of the input shaft which was causing 5th to pop out all the time..
And that was over 2 years of giving it a hammering, and a fair slab of horse power through 4500rpm side step the clutch launches..
as for AWD taking the skill out, it doesn't, unless you know how to drive you won't get a quick time, be it drags or a motorkhana, you can be quicker than someone with 3 times the horsepower if they don't know how to peddle it to begin with..