Ok heres my review so far. Im 80% done with the campaign on Heroic and to be honest the game isn't that hard which is okay with me. Almost all the missions are extremely action packed from start to finish with many fun objectives, the only mission i have hated is that stupid *!+ Spaceship mission where you fly a plane and shoot stuff that level almost made me turn off my xbox.The AI for the covenant(the enemy) is insanely smart and no longer free kills, for example I stuck a Elite running for cover and the second i stuck him he turned around and rolled into me killing me. Also with the removal of the dumb talking of the covenant the game is more suspenseful and adds the monster type feel to Elites. Lastly for campaign I kind of feel its a tad bit short, but that's okay with the amazing amount of gameplay and options from forge to firefights and co-op campaign. The campaign/story is a MUST play.
Now the mulitplayer so far i have only played 6 total matches 4 being ranked 2s and the other 2 being Social slayer. From what i got from the social slayer matches is that everyone who plays social slayer is utter garbage, I think i went 25-3 and trust me im only decent at this game,but when i went on ranked the competition was great and every match i played would end in either 25-24 or 25-22. Always being down to the wire and requiring a lot of communication with your teammates. This aspect alone makes the game worth buying, once i played that first Social Slayer match i was addicted i had to keep playing and try out the new maps ( out of the 6 maps i played 2 were repeat, 2 were new and nice and 2 were remakes of halo 2 maps which was okay with me). I haven't played the firefight mode so far so i won't comment on that till later but if ANYONE is on the fence about buying this game go out and buy it right away its worth every penny.