I also do think that the bearings play an important role in the durability of the diffs. When the bearings start to wear and the play increases the gear mesh will suffer from this and start to wear. In my case the bearings were completely destroyed, and the bearing balls got between the gears, the results speak for themselves.. lol . That's one big advantage of 1/8 diffs, they have much larger pinion bearings, usually 16x8x5 instead of 6x12x4, that's a huge difference in strength. I'm also thinking about getting some Boca bearings for my diffs and motor, do you have ceramics?
I'm running with my slipper 1/4 from fully tightened and with badlands by the way. I try to be as smooth as possible with the throttle, but do like to do jumps and accelerate hard from time to time.