less lag (would be nice if we got dedicated servers, but despite being filthy rich, Infinity Ward AND Treyarch are too greedy to spend money on them
Better balance (no more across map shotguns, quickscoping up the butt, certain weapons being head and shoulders above their counterparts, etc)
no more handholding attachments (target finder, heartbeat sensors, scanners, etc)
more of a cost for equipment like claymores, bouncing betties, shockcharges, etc (cod4 handled this nicely by making things like this take up a perk slot)
More maps like COD4 and Black Ops 1
Another beta. Seriously, we haven't had one since WaW. I know most people just use them to play the games early, but they can seriously help out. Don't be arrogant, IW. You WILL have many problems at launch we could've caught and done away with before release
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Like multiple attachments and being able to make our own emblems. Keep the emblems, IW, but continue making the cards with silly titles on them. I hate how black ops 1 and 2 don't have them. (Just no more weed puns)