Gun fire / Smoke Slow down in Retail but not in demo

[Prowlinger]

Anyone notice the smoke FX on bullet trailers really lag / slow down the game when in heavy firefights? The demo didn't do it ... but the retail.... really does lose about 25 fps when you are firing at enemies and there are alot of bullet tracers on the screen also.

Is this something that 1c plans to fix or is it as good as it will get?

I have only played single player missions but it can get horribly bad at times... The 360 demo never did this...