Quoted from rai:
Woz for me once you go color changing inserts it’s hard to go back.
MET Pre has pretty color changing inserts as well - not all of them, but all of the spider inserts are and the game uses them well to indicate modes.
My vote is for MET Pre. I've played WoZ on location many times, and I just never get into it -- I find it boring. It's gorgeous, but just not fun. MM is fun on location, but I don't think it's deep enough for home use personally. MET Pre is just awesome - the hammer smashing the ball under the playfield is still cool after having the machine for almost two years.
That said, if you've played WoZ before and really like it, and that's the way you're leaning, then go for it - plenty of people love the game.