I'd like to buy BF2(complete collection) on Steam, but the friend I'll play with said it's not compatible with the "normal" version.
I've read somewhere there's a problem with steam chat + punkbuster, and I wonder if just disabling steam fixes that and I can play normally, or there are other issues.
Furthermore I wondered if getting the Steam version you are given a user+password that you can use also on "normal" clients, or you would be stuck with playing it only on Steam.
So the actual question is: what are the differences and the compatibility between the Steam and the non-Steam version?