If it is the ISP, why would other games run fine, and some not run? I seriously doubt that MW3 pushed the boundaries of bandwidth limitations and all of the sudden this game has become unplayable...
My router says 0.0548 megabits per second upstream even less downstream. The greater upstream surprised me. Maybe I was host.
OP, I think you need to realize that we have been playing on "Crappy" copper core cable for many, many years, and never had problems until this game. Well, Black Ops had it's fair share of connection problems as well.
From experience COD 2, COD 4, WAW, and MW2 never had problems like the last two installments of COD have. I would say MW2 hit detection was the best.
Also realize that turbo or power boost, really has no effect on the game, as they are increasing bandwidth. Bandwidth has absolutely nothing to do with ping, which is what is important.
This game just doesn't work properly online.