Why is the Javelin so unrealistic in ArmA II? Even CoD4 got it way better. There's no waiting, the viewfinder is nothing like the real one and you can't select between top attack and direct attack.
And then about suppressed weapons (or "silenced" as it's referred to in the game.. might as well call magazines clips too :P). The suppressed M4 should sound very loud even with a suppressor, the noise just "flattens" but the massive sonic bang is still there. You'd be heard instantly. UNLESS however you use subsonic ammunition, in which case it still doesn't sound right (it sounds like an airsoft gun, instead of a hard bolt sound), and also if you use subsonic ammunition, the rifle won't cycle and you'll have to pull the charging handle after each shot. Instead you can fire full auto with something that sounds like a subsonic suppressed .22LR but is as powerful as 5.56mm.