Bear with me on this, I'm trying a bit of optimism.
Maybe all of these FMG9 akimbo users are just ignorant of the fact that people think it's OP. This realization came to me when I read on here that the FAMAS was OP apparently. I only joined the forums after I looked here for opinions on MW3 so I never knew public opinion on the gun. Therefore, maybe these people are going by the "they're doing it so I'll do it" mentality and using it to enjoy their "pro status." That or they're trolls
I personally think it's OP because of this chain of logic: RoF is the determinant stat. Even if the range isn't top-notch, if it is weak, and if the accuracy is bad, a very good RoF can just fill up the missed areas and compensate for damage weakened by range. FMG9 has very high RoF. Toss akimbo in there and, like I said before, accuracy and range are insignificant problems. I'm fairly certain that all you need to do is have them (somewhere) in your crosshairs and they will die, no intricate aiming required as with other guns. Sure you can try to counter with range. But really, MW3 maps? No. You can counter with skill but with a RoF like that, your best bet is a OSK. Shotguns are underpowered (too many close range shots that don't kill) and quickscoping just ain't fast enough for cheetah reflexes. Pretty much, I got nothing against the gun without akimbo, it's basically an SMG. With akimbo though, the need to aim is taken out in exchange for loss of accuracy that is already compensated for by RoF which is doubled. It's worse than pre-patch Model 1887 akimbo from MW2. Infinity Ward just doesn't learn. If they make another game, I'm joining the boycott of it.