I have the same current problem but what a problem to have!!
I'm 43 and have always wanted a new, affordable manual V8 with a few creature comforts since the heady days of the 70's. I however believe that the XR6T auto would be more acceptable to my wife, and presents a more presentable professional and modern image with better resale. The XR6T is I believe the better overall package (and yes I have driven both) - but I'm going to go the XR8 because I will be disappointed if I didn't satisfy the long standing V8 dream. XR8, leather, premium sound 18's.
GT is $18-20,000 more to me and for that money a 2nd hand BMW is the smarter choice (for me).
The only problem now is colour - Red, Orange, or Citric Acid.
Horses for courses. The difficulty is assessing what car you really NEED (rather than want) and can live with as a daily driver.
Good luck and tell us what you decide and why.