Got them the day they came out as a DLC, the DLC's are like a few hundred Meg each. They're not all the great, awesome new content but the Campaign related stuff is just unappealing all together like all of Arma's campaigns. I only play Arma 2 OA Domination, anything else is just unenjoyable and tries to go into other FPS territory which Arma does not do well at all. With the exception of PVP with pre-set mass clan fights.
DLC isn't worth it, you acutally get all the DLC's Lite versions which allows you to play with people who own DLC though the graphics are quite stuff in relation but you normally wouldn't have your settings on high enough to truly care.
