Didn't find it that hard to go back, I enjoyed my time in BC2 but prefer MW2 since its the only multiplayer I've really gotten into since I was much younger. BC2 is a brilliant game though but it is in no way similar to the CoD games. The only real similarity is that both are FPS games with a modern aesthetic.

after playing BF:BC2 I feel like I've grown out the mindless madness of COD, I'm not saying that COD is bad or anything, its just that, at this point whenever i try to play that game i cant focus it feels like everything is very bland and basic.

If BFBC2 had the same level of polish that MW2 has then it would be hands down the best game but it's now a couple of months after launch and BFBC2 still has major issues with it's interface, server searching, performance and balance.  The latest patch has improved some of the server and UI problems but the performance has gone down the toilet and balance is just laughable for certain weapons. 
 
Until they sort these problems I'm going to back to MW2.

can anyone play mw2 at all? 
its so horrible

see its still cool to hate on it 
 
though the games have the same theme, they are completely different experiences and as such i can very easily enjoy both 
the bar was just set so high by mw1, mw2 was doomed to fail in the eyes of whiny internet fanboys from day one 
also team tactical is mad fun

I play MW2 for stupid fun, and BFBC2 for the awesome moments (some of which are stupid fun) and game play.