I live in one. It was built by the previous owners (literally...not contracted out). Ours is a stand-alone house without an attached shop/barn.
Regarding durablity...ours is about 4 years old. We've been here 2 years, so I can't speak for long-term, but I love living in it. We have a much bigger and nicer than we could have afforded in a traditional home. The maintenance is practically zero. Our energy bills are suprisingly low.