i never broke my 5.29's in the 7 or so years i wheeled them. its all about the setup and good gear set.
i ran us gears in the rear with a detroit and richmonds in the front with an arb.
i broke an e-z locker, multiple birfs and inners, broke a first gen welded cryo'd long and broke a 30 spline long. my 5.29's took it all and kept ticking. and i am not easy on my junk, multiple trips to the hammers, rubicon ect.
i have known a few people that have ran 5.71's with no issues. i think a lot of it is hype over the small pinion of the 5.71's.
we need someone to set up a test rig for ring and pinions. i bet we will see more issues with brand than with gear ratio.