Depends on what you want man, in your initial post your not interested in a track car but a daily driver IMO the F6 would be more suited to you. There's alot of potential as well, that same F6 your talking about got a upgraded dump-pipe/cat + retune and made 335rwkw not bad for something like $2k worth of mods. The F6 won't handle as good as the GTR we all know that, but they don't handle bad either...just not as good as a GTR.
All depends on what you want outta the car, for a quick daily you can't go past the F6, for more of a weekender/track car the GTR would come out on top.