Well, the others have pretty much covered it . . . but I will add LONNGGG burn times without having to reload. Now, the same could be said for electric or gas but with the UDS you get that great charcoal flavor. Once it is lit it is darn near as steady as gas. Doesn't react as quick obviously but they are pretty darn stable once they get dialed in.
I think my favorite though is that a UDS could care less if it is windy or not.