Changing a tire about once a month on my derailer bike convinced me to get some Schwalbe Marathon Plusses for both of my bikes. Since then changing the tire hasn't been an issue at all. Gear hub or no.

Certainly that's something to consider, but also if you have to change your tire often enough for it to be an over-riding concern, you may consider some flat prevention. My Nuvinci wheel is a pain to remove and put back on, largely because of the shifting mechanism combined with my chain tenionser, rack, and fender mounting points. I try to come prepared to change a flat, although it will be a longer process than on a quick release tire, but so far it hasn't been an issue.

Other hubs have it easier and wheel removal is much like any non-quick-release wheel with an extra step to unhook the cable. I do miss the convenience of quick release, but then considering I park my bike outside often, I do like the extra security of knowing my bike can't be stripped as easily as some.