someone I camped with at the hammers broke a rear shaft with some generic brand 35" tires and he drove his truck real easy.  another thing about the chromo shafts it they resist bending by the flange better where the stock ones will bend from jumping or hitting things like mine is.

It is a rare thing, breaking rear axles.  I agree, they are STRONG!  Made out of stout material where most OEM stuff are much weaker.  My junk is heavier then most Yota's.  Close to 5k lbs with two people in and when you think of the brutal weight transfer when crawling a steep climb, I think the chromo rear's are a safe bet.