Beat the campaign just a few minutes ago. I loved it, easily my favorite of the series. Spoilers below...
Loved how the end was a homage to the Maw. Although, needless to say, I'm glad there was no time limit.
The Flood were interesting. In Floodgate, they're fairly easy to kill. In the second to last level, they're much, much harder. I especially hated those wallcrawling scorpion/ranged guys. They really
got on my nerves.
No! Miranda and Johnson die! It was nice to see Truth's ass handed to him, courtesy of good ol' Arby.
Make sure to stay tuned after the credits, there's a nice little scene if you're patient. Master Chief lives! Leaves a small possibility for another sequel, too.
Assault Rifle was neat to see back in the Chief's hands. Sucks that the clip had to be cut in half, same with the Boomstick. Gravity Hammer was amazing to use. I loved being able to blast away entire squads of Grunts and Jackals.