I'm not impressed with Arma2 armor ballistics or damage models. All tanks pretty much have a hit point system, instead of armor/penetration calculations.
The mod team previously created the OFP mod
Liberation 1941-1945, which featured an armour model based on hit location and armour thickness etc., rather than mere hit points, and tank gunnery to match. There were other features, such as mobility kills, repairs by tank crews where possible, and lots of other good stuff. As the scripting for ArmA2 is similar to OFP, I have high hopes that much of this will make it in again.
http://ofp.gamepark.cz/index.php?showthis=8502I played the original mod a fair number of times, and honestly, it really was quite a bit different from stock OFP. With the improvements offered by ArmA2/OA and hopefully the same development philosophy, this could be a superb game.