Re the ax10 shafts, a guy on rccrawler makes cro-mo 6mm outputs for the tranny, alloying you to run revo or max shafts. Never break em :P
The stock shafts don't actually break, but the plastic pieces do pop off the yokes in a bind. A $40 set of MIP C-Splined driveshafts cures that issue easily though.