-Most guns are balanced, seriously you could do well with almost any gun -Unfortunately, most of the maps in this game are close combat, so the SMG and shotgun reign dominant (doesn't mean you can do bad with an AR though, I use the M8 and I destroy every game) -This game is harder than all the previous CODs (doesn't mean its a bad thing though) -Killstreaks are actually really hard to get, you can't spam them at all anymore, the good thing about them being hard to get is that they are really good and you feel rewarded if you get them. -Shock Charges and Bouncing Betties are moderately OP in this game (overused. but a lot of people are starting to use Tac mask/flak jacket, so its balancing itself out)
Overall, its a really fun game, just some stuff needs to be sort out right quick, but even still its better than the previous CODs IMO.
Best game ever: http://www.youtube.com/watch?v=3ZhnGQXWi1U&feature