Puff has the advantage against zelda in melee. It's not as terrible for zelda as some of her other matchups but she gets destroyed by WoP and she doesn't have a good way to punish rests so puff can throw it out there without worrying too much. I agree that she'll definitely do better in the MU in project m but she certainly wasn't great against puff in melee. Play against someone who knows the zelda matchup and you'll see how frustrating it is.
http://www.youtube.com/watch?v=dfLYmVaj1Tk
Zelda is amazing in project m though. I can't wait to go to a project m tournament in norcal (whenever it happens) now that I have transportation. I haven't played any super experienced smash players yet but I don't think zelda has almost any bad matchups. Marth and fox are still probably tough, and mario might be difficult to deal with as well (for no particular reason other than the fact that he's a solid character in P:M).
I've been playing for a little over a week now with every character in the game and I'll probably post some ridiculously long analysis of each of the characters here in the near future. Probably gonna revive my dead youtube channel and put up project m gameplay videos as well.