GTS all the way - only because I prefer the sound and the way it drives.
Driven both and it's just a personal preference thing IMO. Both are seriously quick!
Coming to the conclusion that one is superior to the other is complete rubbish!
I went through a similar dilemma re: XR6 Turbo or SSV etc.
Full exhaust, OTR intake and a mafless tune really open them up. Once you get board of that - a decent 23x cam will see you laughing
Holy shit I've turned into a trev - I think I need to see a doctor!