The Univega is a good deal but I am leary of buying something like a bike frame without being able to inspect it. I have ridden a 17.5" MTB (Giant Sedona) and a 19" Marin and Klein. The 19"s fit me pretty well but the the Klein (for all the things I like about it) is just beating the crap out of me when I ride.
I came really close to getting a Bianchi road frame (that I just thought was great) a while back and I wish I could remember what size it was and just recently I owned a Softride bike (I worked for them) but I really didn't care for the whole suspension beam experience.

Good point about the cost of a rebuild...I HAVE all the parts from the Klein that I can move to another MTB frame. About the only thng I'll need to do is change out out some of the chain rings that have broken teeth.

FWIW, I am planning to see the Centurion (I find the idea pretty compelling), but I am leaning toward a Giant Sedona for about $50 that I am also seeing.