BO2 multiplayer is still better than MW3, trust me i know. More balanced, but same mind torture as in MW3. Basically treyarch fixed the problems IW left in MW3 but not really improved fully. I am sure you get the point.
And if we were to compare BO with BO2 then BO2 has a much better gameplay and a maojr leap from BO.
As for the FREE key, I am touched. Thank You, Really. But not really a use for me :)
But hey, if you can "Transfer" the game to MY OWN account then you are welcome to do so :P (which is not possible -- so back to square one)
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I also own BF3 and its just preposterous. Even after 1 year, its more torture than COD games. Seriously, we PAY the frigging money and still play in higher pings. Ironic. Situation would improve much more if the servers become available locally. And to me, COD games still have a better gameplay than Battlefield style. Atleast we can play as a Loner ;)