My biggest issue with Match making is how god damn long it takes it to fill groups and start games.
I don't mind a bit of a break in between matches, but when I feel like I need a book at my side before I load up Halo 4 I feel like I'm being robbed of time.
I'd love a skill ranking system vs the system they have now, which allows any old clock puncher to "level" up, with an ELO matching system for more balanced teams/matches.
BUT!
As it is now, with them selecting any old crappy connection host, filling one team with 6-8 rank 100+ players and the other 8 kids sharing two xboxes, it still takes 5 minutes for them to start a match.
I'd just like to get more games in, and if they'd turn around matches a bit faster (i.e. fill groups that lose players after a match in less than 2 years) I think that would be an amazing start.