Really? MW3 is by far my least favourite Call of Duty game.

There is absolutely no variety in maps; they are are all roughly the same size, very cluttered, with no sort of verticality, and often contain chokepoints, where the fight will be continuously pulled.

The weapons are imbalanced; whilst in past games, some guns were seen to be better than others, in this game due to longer average kill times, some guns far surpass others, and many are just not viable as competitive weapons. Addtionally, too many weapons are exactly the same, or one is clearly statistically slightly better, making the other useless, eg. M4 and SCAR-L, M16 and Type 95, L188A and MSR, all SMGs, AK-47 and CM901, the ACR and all assault rifles, all shotguns, .44 Magnum and MP412.

The weapon levelling system is tedious, and many of the more desirable attachments and proficiencies, some of which (like damage on shotguns) are the only way to make the weapon effective.

Killstreak spamming has become much more of a problem due to the Support Package and Hardline Pro.

And finally the spawns are just horrible, and I don't even know how they screwed them up. So many times, in TDM or FFA, the enemy team will spawn at a site where somebody is already located, or you'll spawn within line of sight of the person who just killed you. Even in Faceoff, when there's only 4 or 6 people on a map which is still fairly large you can still spawn where the entire enemy team is only metres away from you, even when you could've been spawned anywhere else and been safe.