Yeah, that was a stupid question. I mean, this game is a military simulator so actually being in the Army is big pro. You got tactical training, know strategy.
I only kill if threathened. Aim at me, I will shoot. Shoot at me, I will shoot. You just walk by and don't see me, I hold fire. You have no weapons or hatchet, I don't fire.
Wasn't a investment for me. Already had CO before this got released but I think this mod is insanely awesome. It is survival so there is unrestricted PVP. If you go to the server list, it's almost all DayZ so it is also popular.