"I bought it for a 100 mile section hike of the Appalachian trail in GA and NC in 1999. I have setup last in a shelter several times and was still first to get eating. It uses ISO Butane so there's no liquid fuel to bother with, is much more controlable than white gas or mulifuel stoves and boils water fast. I had one problem with it in 4 years. The control knob came off in my hands on a hike this summer. When I got back home I called MSR and they shipped a replacement valve at no cost. The only real downside is finding fuel if your on a really long hike (like a through hike on the AT), but an 8oz can last me at least a week on the trial, longer if you actively try to conserve fuel (boil, cover and wait instead of simmering.
In short Good stove great service, no real gotchas."