@Destinyheroknight: Not necessarily. Final Getsuga Tensho is the move he uses to combine with Zangetsu to launch the FGT. He has no feats moving around using the form, so it is just a technique he uses. Naruto's Nine Tails Mode is stated specifically to be a mode, same with Nightmare Luffy, though he isn't being used here. FGT is not, in my books, a mode. Post-Dangai, definitely. Final Getsuga Tensho? Technique, not mode.
I don't consider FGT Ichigo his peak form. 1 it was merely a form he needed to execute a particular move. 2 he has no feats in that form to prove that he is at his best there. His best feats are from his Dangai form. Think about it. If Naruto or anyone else has a better shot at beating his FGT form rather than his Dangai form, isnt that indirectly saying that his Dangai form as a whole is stronger or at least more effective? (which it certainly was). Besides, even if FGT form is Ichigo at his best, he doesn't actually lose his powers until he uses mugetsu.
That's exactly what it is, thank you guys.
Ichigo wins either way.