Before the Rockets I had an R1150RT and then a R1200RT. I spent a month agonizing over which bike to keep, the RT or the Rocket. Both great bikes, but I've never looked back.
I remember in the BMW forums the final drives were notorious for going out. Thankfully, that never happened with my Beemer. On the other hand, you'd be hard pressed to find a post about a final drive going out on a Rocket 3, BUT if you look hard enough there I'll be.
I think they all have issues and sometimes it's just the "luck of the draw."
I've had my fair share of problems with the Rocket, but I run her hard and put on a lot of miles. It seems about right.