Going from a much more tuned shooter like MW2 to BF:BC2 is kinda like driving a high end sports car and then getting into a 2000 Ford Escort.
The controls aren't anywhere near as sensitive, the running is funky to me, the melee attack takes forever and a day, lag is incredibly noticeable and you won't get a OHK shot on a sniper rifle if its not a headshot, especially if it's a neck shot. Can't lie prone, jumping is just weird and not really natural, the gun sights are crappy when aiming down them, having pull the bolt and ready the next shot on the M24 after every shot while is a realistic touch, having to manually do it is retarded, where as the Intervention just isn't. The multiplayer radar is pretty awful, explosions don't do enough splash damage so you have to actually hit a person with an anti-tank round to get a kill and the tracer dart isn't a homing dart, just an aid for the increased chance to hit with the RPG compared to what one of the trailers showed. I couldn't leave a squad nor mute one annoying player, so that just sucked since I had to listen to him prattle on the entire session. Having to swap out your whole kit instead of just taking a gun in place of your primary/secondary sucked too.
The gameplay in multiplayer seems lacking, I'm hoping it's because it's not the final product, I have it preordered at Gamestop but we'll see where it ends up. MW2 may have spoiled me too much, I want a war game, not a glorified HALO replacement. Hopefully this won't be the case.