I'm not sure how I feel about stapling completely separate characters together with a transformation button, especially since it will almost certainly NOT be instant like it was with Zelda and Sheik in Melee. Unless Crusade sees some top tier optimizing in the coming builds, I can't imagine it being anything but unfun waiting 5 or so seconds for the switch to take place. That's how it was in Brawl with Zelda/Sheik and Pokemon Trainer, and my enjoyment while playing them actively suffered when I transformed.