Halo 4 was an amazing game that didn't do much wrong. What it did do wrong was far over shadowed by what it did right. And dear god they better release the next installment on 360 as well.
The bad. Forge wasn't very good.
The good. They added a new feature that I call sprinting. it's an amazing thing that makes this game that puts you in the middle of a war between humans, aliens, and gods, a lot faster than the other installments. It made the game more fast paced when it needed to be allowing you to have slower paced moments when needed. I loved the game for how smooth the movement is, the fitting soundtrack, and all new weapons that you get. I loved it. It is deserving of the title, the best in the series.
Final Verdict:
Buy the game. It's an amazing game, and even better if you have played the rest in the series.