I've got a used T-5 out of an 89 V8 camaro with an s-10 tail shaft behind my 454 and have been driving it for over a year. I don't do hard launches, burnouts, or powershifting though, but that being said, I haven't babied it that much either. I figure it will eventually go and I can upgrade from there. Not sure if I will try to rebuild it or try something else. It was a really easy swap and cheap. Oh, I also run syn in it.
I have come across a variety of advice to different people about the T-5 on different forums/websites. Here are a few articles to check out as well...
http://www.fordmuscle.com/archives/2005/12/T5Rebuild/
http://www.mustang50magazine.com/tec...ion/index.html
http://www.fordmuscleforums.com/all-...ealy-take.html
http://www.gforcetransmissions.com/tran_gt-5.asp