I'm going to be biased here, seeing as most of my attention has been on one character, but I'll give my thoughts anyway.
Unlike newcomers, Falcon players had already been playing a similar (yet very different) Falcon in previous smash games. Having said this, its been difficult for some of those players to break old habits. Falcon is played completely differently this time around. He can't be as offensive as he once was, and he's got to rely on grounded attacks rather than his aerials. On the surface he seems much like the same, but the truth is that he is hardly the same character he once was.