Disclaimer: I have never toured with a Rolhoff and never owned one. In fact I hadn't seen one before two months ago.
Since then I have ridden for 10 days with a couple who both have Rolhoffs, and am now in a guesthouse and have talked to many Rolhoff riders, and looked closely at them fixing their bikes and talking about problems. The guesthouse, Nomad's Guesthouse, had 20 bikes here one night, 12 of them were Rolhoff bikes. Most are Europeans who are waiting around for a China visa.
I thought I might list a few things I have noticed.
1) Rolhoffs are heavy.
2) They seem to break more spokes, this might be, as one guy says, because the spoke holes in the rim need to be at a different angle than normal so you might need a Rolhoff specific hub.
3) There are a few shifting foibles, if you change up two gears and dont have a tiny pause between you may end up in 14th gear.
4) 7th gear is noisy!
Three types of setup
1) Non Rolhoff dropout frame with a little spring mounted chain tensioner, the least good method.
2) Adjustable dropouts to tighten the chain as it wears. Make sure each side has 2 bolts. Bring a spare or three.
3) Eccentric bottom bracket. Two types,
a) two screws that dig into the bottom bracket to keep it in place, not the best solution as you end up with a series of small divits in the bb that make it harder for fine adjustment. Have spare screws.
b) Split bottom bracket housing with 3 or 4 bolts to clamp it closeed. The best method. Have spare bolts.
One guy's Rolhoff, with a belt drive, died. Bits of something from inside were pushing into the casing making sharp little points. He called the bikeshop where he got his bike from, they contacted Rolhoff who sent a new one to the shop, the shop put it into a wheel and gave it to his mother. She was flying to Almaty in Kazakhstan to meet him, so he had a 500 km truck ride to get there and get a new wheel.
Would I get one for my next bike? Not sure yet, they are heavy, but there are savings on maintenance.... still thinking about it.