I'm not sure if you went through the whole thread or not. I am 100% function over form. The reason I took it off the roof: at Moab in 09, while in Poison Spider, there is a little rally run, like a mile through the sand, and we were moving pretty quick. I saw something in my peripheral (and it wasn't a blonde). We slowed down, turns out, it was a bolt from the roof rack that had gone flying off. Then I started thinking about 70-80lbs of rim and tire on the roof and what that would do to someone if it came off the roof on the street. That could be deadly.
Plus, having the tire on the roof with no cover on it means its in the sun all day long, which will destroy the tire. But I do trail the VX with the spare on the roof for approach angle purposes. Its also a lot easier to get the spare off the door, I got a dent in the side from trying to get the tire off the roof by myself a few months ago.