I've wanted a TIG set up for years but could never justify the cost. Now that I can afford one, I'm so used to use an Oxy/acetylene set up I still always decide to spend the money on parts or projects instead...
As torches go I really like the Midget. It was pretty inexpensive and TinmanTech has all the tips and other bits for it. I've used it mainly on thin stuff or for brazing but one of it's most recent uses has been welding up a Model A frame. It worked fine for that. I think they say you can go up to 1/4" thick with it but that's not really where it shines. 1/8" and less seems to be the sweet spot for it to me.
It's already been mentioned but having an O/A set up around for other things is handy. Until this car project I probably used my torch for things other than welding at least as much as I welded with it. Heating kickstart levers to reshape them, brazing up leaky tanks, that sort of thing. Even if I had a TIG I'd still keep the torch around.
I find welding with it to be relaxing even. Get the set up right and there's kind of a zone you get into with the flame and the filler rod. (Sometimes getting the set up right is frustrating though, but thats all part of it, isn't it?) The very little bit of TIG welding I've done is similar I suppose but there's something about working on 80+ year old stuff with a flame that seems right to me.
And having said all of that, the main reason I still want a TIG is to weld up stainless exhaust systems. I STILL shop for a TIG set up a few times a year!