The other thing to consider is the power to sales ratio.
Honda sells more accords than Nissan does Maximas, so Nissan puts more power out of a bigger motor as a selling point. It is a common thing. Chevy makes more power because they can't recall peoples love of old Camaros. Are there half the people who take real pride in the mid 80's IROC's? Are they guys with mullets?
When you vehicle is selling, you don't really mess with it. Truth is, the v6 is what is keeping the mustang alive. That car is pretty useable in terms of a mid 20's-30's woman driving it to be in something 'sporty'.
I figure the above will get me flamed, but the F-bodies were just too much hassle to get in and out of for people who want a car that looks cool or fast. I've driven them both, (test drives man, test drives
) and the Mustang is much more liveable.