Let me preface this by saying that I have really enjoyed Halo 4 so far, and that i do not really have a problem with the general direction 34s has taken. However there are some issues that need to be addressed
1-In game joining: This featured was taken from COD. It worked in COD because it was a more individual game where a player could succeed without their team and still have fun. However in Halo 4 in game joining just results in players finding themselves stuck with a crap team halfway into a loss, which is not fun at all. A larger penalty for losing, such as subtracting EXP, would help solve this.
2-Instant Spawning: I assume 343 wanted to up the pacing by letting people get back into the action right away. However, I have found that is screws up the spawn locations. It has become annoyingly common to spawn on top of an enemy, or have an enemy spawn on top of you, especially on free for all games.
3-Playlists/Custom Games: One of the fantastic things about Halo is the variety in the multiplayer. This is not as true in Halo 4. Right now the playlist options are severely limited compared to the past games. I hope to see some new options like Grifball and Snipers added soon, among others.
These are the three issues I would most liked to see addressed, although I’m sure there are many other opinions.