I have heard many times of a catastrophic or at least serious derailer failure on the road, requiring maintenance. And yes, derailers are fairly easy to adjust and maintain in such an event. But I have never heard of a single catastrophic failure of an epicyclic hub on the road. That doesn't mean that it never happens, but it is extremely rare. This argument is brought up a lot by people who don't like internal hubs, but it's really no argument at all. It's a complete non-issue with any decent internal gear hub. I have not had a single problem, ever, from my S-A AW hub on the road. I haven't heard from users of other, newer hubs who've had problems. On the other hand, I can recall a few occasions where I've had to get off the bicycle and get my fingers dirty putting a thrown chain back on, or fixing a bent derailer hanger, or correcting any number of problems. Commuters on this board have mentioned having to make their derailer bikes into singlespeeds just to get home or to work. Seems to me that this dog doesn't hunt.