Mike, you should do what I do. Have no 'bias' or heritage of a brand name. Believe it or not guys, I am not biased towards GM/against Ford. I love Mustangs, and if they had a targa top (wouldn't look right with T-Tops) I'd have one... I just go on looks mostly, and to me the Firebird looked better than the Mustangs.
(Don't flame me for this, it is the truth) :
The performance aspect of the Mustang GTs are somewhat slacking compared to an LS1 Corvette or F-Bod. But that is nothing the very cheap aftermarket of Mustangs (especially 5.0s

!) can't fix in a heartbeat. Aftermarket parts for an an LS1 are about twice as expensive, and there is less of a selection. I guess it evens out.
Anyways guys, that's truthful, don't kill me for it.