Wario's good for mindgames. He's basically a fusion of Melee's Bowser and Jigglypuff, from what I've heard, with the size, range, mindgame potential, recovery, and attack speed of Jigglypuff (though sadly he isn't as good as pursuing in the air due to him only having two normal jumps instead of five) and the weight and attack power of Bowser.
Meta Knight, meanwhile, has Kirby's weight, speedy attacks, a disjointed hitbox similar in length to YL's (if I'm not mistaken), is a small target, and has a recovery better than Wario's. However, like Wario, he has a limited range (though not as bad as Wario's) but is relatively straightforward and doesn't have the same mindgame potential as Wario.
Correct me if I'm wrong on anything, please.