Not sure geared diffs are a low maintenance option from what I'm told...they need refilling regularly to keep them consistent...if your sensitive to the feel.
I have always found the AE ball diffs to be very good on maintenance...I never had an issue and only ever worked on them every 6 months to a year...and that was with weekly club meetgings, regionals and nationals.
I should probably have done more work on them...but I'm a lazy mechanic! They've never failed me though...only thing I've ever seen was a pair of crown gears wear out...but that was after a lot of use!
Now driving a Yokomo, the current 4wd and ball diffs have been bomb proof so far...only thing I've broken on the car is a front shock tower...and that was after a very fast crash that could have broken a lot more! Very easy to drive and parts are now very easy to get hold of.
