I've driven an 05 GT before. Stock. I wasn't impressed. It didn't feel any better than any of the 4.6s i've driven thats for sure,

 

Get the mach. I miss mine so much. I regret everyday getting rid of it and buying my 07GT. Once i pay my 07 off im either going to come back to the mach or get a 04 cobra. Not to mention with all the mods i had on my mach it would spank the sh*t out of my new car haha