After having played ARMA 2 CO ACE + Jarheads sound pack. yes, oh my bloody bleeding ears yes to all and any bullet cracking / snapping. It feels very good, and it also lets you identify how close a bullet passed to you ( bullets that pass further away do not produce a snap to your ears ). beyond the immersion / realism aspects, it also has the SIDE EFFECT of suppression, you want to get down when you start hearing the cracking.
As an aside I also like the actual suppression effect that the game uses for the AI and Players. Getting shot at by large quantities of ammo increases your weapon sway slightly ( increased heart rate, it makes sense). This actually adds credence to using a machinegun to hammer a position where some enemies are hiding, even if you can or cannot hit them, urinating 5.56 rounds over their heads means any shots they do manage to squeeze off will be inaccurate for good reasons. The DH system was a good stab at a suppression system, but IMO went too far, someone who has never been shot at before might twitch when shot at, but that's an effect that would quickly wear off, besides also being very annoying.
