Dude... let me just say that you have not experienced XBOX Live if you have not played this game Live yet. I play this game for hours straight online. Tons of maps to be played, tons of weapons, and my favorite part is that you get points for kills and capturing flags and such, that it tracks your points and raises your rank accordingly, so you are playing with people your own skill level. There are also medals and ribbons you can get online.
Now single player this game also kicks incredible ass. Same sort of style as the online only in mission form. Ive just seen it go down in price at EB Games and GameStop to $17.99 so its definatly a must buy.
No, I cant say that I have played it for the PC. I've played the old Battlefield Vietnam on PC but never BF2. Sorry, but I cant help you with that one. Ill check around with some of my friends and see if any of them have tried it out. I'll let you know if I find anything.