I’ve been a Halo fan ever since I played Halo: CE back in 2004. That being said, I have mixed feelings about Halo 4. I love the new graphics, and the controls did not take very long to get used to. The loadout system is great, and it’s finally nice to be able to pick which upgrades I use. That being said, I have a few problems with the game.
-There is no campaign matchmaking: Really, it’s kind of depressing that I can’t find someone else to play through it with.
-Spartan Ops is not a very good replacement for firefight: I like the idea 343i had with spartan ops, but it is not as fun as firefight was.
-The playlist for wargames is dissapointing and lacking compared to Reach’s playlists. Specifically grifball.
-There aren’t very many map configurations, and the matchmaking doesn’t use any forged maps. (My favorite maps in Halo:Reach were forge world maps)
-The forge maps are small and have too many things in them, like buildings that can’t be deleted.
-The thruster armor ability is basically useless, I can barely dodge a ghost with it
-There are no UNSC flying vehicles available for multiplayer
-Vehicles missing (RIP Revenant and Falcon)
-There is no invasion mode. I get that dominion is supposed to replace invasion, but really it’s more like king of the hill.
-There is no king of the hill in matchmaking. 
-Lack of map diversity: I feel bored playing on the same maps. I wish matchmaking would allow for the use of forged maps. Also I want a new forge map or two, that would be exciting.
Despite all of these problems, I still feel that it is a great game, and I will continue to play it, even though I feel that it has yet to reach it’s full potential.