What year GT are you comparing to? If it's 99 vs 99 than no comparison. The cobra is definitely the way to go, as mentioned, 4V, IRS nicer seats etc.
I would also consider a Mach 1. Similar to the Cobra minus the IRS and has that b*tchin shaker hood..there aren't too many other factory vehicles out there where you can watch your engine slam to the right while banging thru the gears.
12 Black GT500 SVT PP l 2.6 Pulley/Idler l Airaid l o/r X l 305 NT555R's l Recaros l
04 Azure Blue Mach 1 / 03 Sonic Blue 3.8 / 14 Sterling Grey F150 FX4 402A 5.0 / 11 GT500 R.I.P.