This game is amazing! Definitely the best game of the year. Great online, superb campaign and Spartan Ops is amazing!
To start with, the controls are good, but if you're coming to Halo 4 from 3 then you will want to change the controller layout from Default to Recon. If you're more familiar with CoD, then you can change the layout to Fishsticks. The game is very responsive, and so far has had no rendering problems or lag.
The campaign is extremely immersing and enjoyable with a great story. The weapons are cool and have received a graphical and sound update so they no longer look and sound like plastic toys. The addition of Prometheans and Promethean weapons is very cool as well.
The online is the real star of the show. I have encountered no cheating or glitching so far but there is a little bit of camping just like any other FPS. Another great addition is the create a class option, which at first I was apprehensive about but is actually really good, and not as over powered as I expected. There are a lot of new and classic game modes to pick from and all are fun.
Spartan Ops is also a good replacement of Firefight. The short films are very well made and the combat sequences are great, as is the story line which takes place six months after the events of the campaign,
Overall, I think it is possibly the best Halo game to date!