why would you even try to compare the two, especially on a CHEVY forum. there is no comparison between them, the chevy wins hands down. if i had the chance to buy an older impala such as the 95 SS i would def buy it, even if i wanted something else.
so hands down if i were you i would definatly go with the SS, forget the Mustang, unless its the fox body style with the 5.0, but that one is newer then that. i would NEVER EVER touch one. not only that but for a guy mustangs are kinda girlie... stick with the SS and you wont have problems.
thats my .02