So, all it takes is a 2 hour wifi session against someone around my relative skill level to really figure out my best characters for this. Thanks "Eisen" from the chat; those were all really fun games and easily the most fun I've had on wifi ever. By the end it didn't even feel like wifi and it truly felt like I was playing Project M for real.
I'm still loving Wario, and I think I'm starting to get the hang of using him. Looks like my other usable characters are Link, Ganondorf, and Bowser, with a little Game & Watch if I want to break a winning streak. My Melee characters really transitioned well here, and also, Ganondorf dittos are crazy. I still can't get over how insane Bowser is now. I can't wait to use him against people playing P:M for the first time and have them accuse him of being broken.
We played on a good variety of stages too. All I have to say is that Temple:M is broken because you can tech things on the sloped floors at 200% and live.