Halo takes a while but the matchmaking will find a game, it's anywhere between a 5-10 minute wait for me on average. The biggest issue for me at least seems to be the splitting of parties, both pre and post match.
If you go in with a team it will split you up unless you are all together prior to searching for a match, and then after the game it kicks everyone and the only fix I've seen work is to close the game out and reboot it. Really annoying.
there is a glitch on one map where there is a glass elevator door. Some guy found a way to get behind the glass door, you can shoot out but you cant shoot into this elevator... this dude went like 45 and 3 hahahaha