I have worked on all bikes fixing them up for people or resell. I have never found a mountain bike rim that has come apart. Some are bent a bit, but nothing like the 700C or 27 inch. The construction the the mountain bike rim double wall is really durable. I am always having to true a 700C or 27 inch with a hop. I just had to order a whole new rim for a 700C that came apart at the seam. Never seen that yet on MTN rims. Maybe a tad heavier, but if I was touring in remote areas I would want a rim that is not fragile. Another good thing to remember about mtn bike rims, is they are everywhere. If you wiped out your bike on a tour in the middle of nowhere , you could probably talk someone out of there old mtn bike for a few bucks for parts. A 700C has not been around as long and is not so common to find. Walk into a hardware store in a small town and look at the tires and tubes. See any 700C's. Maybe if your lucky. I choose the 26 just because its tough, reliable, and easy to find parts. I tend to like the rapid fire shifting on the old mountain bikes vs the downtube on the road bikes. Just my preferences