I've looked at DCS before, but honestly I like ArmA-2 better.
ArmA does have a hell of a lot of controls that take some getting used to, though. The mission editor is also great (and it is the only thing I play), but it wasn't the easiest thing to learn.
I just wish for two things in ArmA. The planes should have g-loc, and they should have allowed the host of multiplayer games set the view distance as part of the scenario (although there is a mod out there that only the host needs that does just that).
Oh, and Arma-2 has exploded in popularity due to the Day-Z zombie survival mod. A lot of players have it now.