I love Project M. Diverse match-ups are actually possible without giving an overwhelming handicap to the other player. Even at high-level play new experimentation is possible due to less risk of the scales being in favor of the player sticking to a safe and tested strategy.
But I would also like to see less focus on certain things like wavedashing or dash dancing, things that Melee players need to utilize despite them being 100% unintentional. I'm not saying I want people to not use something that is in the game, I'm saying I'd like the game to be built in a way where you simply don't need to or can't. One example is the new way ledge holding is handled. It remains to be seen how that will affect things but I think it's a smart change that will force players into less safe edge games.
Wavedashing isn't unintentional