Miller's an entertaining fighter. He's awkward, and I like that. His ground game is pretty solid, and he throws some nice kicks. His boxing is pretty, well, ugly, but he's definitely someone who doesn't mind scrapping.
Mayhem vs Manhoef would be really fun, and I'm glad Dream scooped him up, since they need solid MW's for their division. Hell, Kang vs Mayhem 2 would be fun.