I honestly believe riding the Rockets hard or using all the power that is in abundance is the not reason we have gearbox problems, it has been well documented that haphazard assembly practices are the Achilles heel of some of the rockets upon disassembling my 2011 Touring's gearbox we found the dreaded chipping/chamfering of 2nd and 3rd gear teeth edges and a spacer /thrust washer worn down to a razer blade thickness allowing massive end float for want of a better description ,my Son who has been doing the repairs said if I had not been so gentle with the bike or not so religious with oil changes and filters the thing would have shyte itself long before the 46000Klms it lasted
if you get a "good" one they are in our opinion capable of withstanding a hard life and have massive inbuilt strength ,but if you are unlucky to get a crook one be prepared for a bit of heartache
hard use or abuse has nothing to do with most failures as mine was ridden always well within the bikes potential ,if I am convinced the reported next generation of Rocket proves to be assembled better at a consistent rate I would buy another one,