I think TT is one of those athletes who has more heart than actual talent. He uses what he has to the full extent while maybe others who are much more talented, maybe don't play with the same heart or drive. The rest of the country is catching on to the phenomenom that has been burning strong here for a few years.
I think he appeals to people because he is the average guy, he's the walking version of where there's a will, there's a way.
As far as comparing him to Vick, while Vic was fighting dogs, TT was building hospitals for children. Does this effect his playing ability? Not at all but it does lend to the mythic quality of TT.
I also agree that his reckless, almost untrained movements on the field will take a huge toll on his body and he will burn out long before his career should from injury.