In my honest opinion, I hate DayZ. The server hosting is crap, the API is bad, and once you get into the game, you have to run 100KM from loving Kamenka to Cherno to grab a car, where you then spend four hours looking for supplies, and once you finally get enough supplies, you risk your car by stopping, getting out, and refilling your gas, where you then hide your car, tent, guns, ammunition, food, and supplies.
After that there's literally nothing to do but kill and get killed by bandits, raid the airfield fifteen times, and even then on any populated server you couldn't do it without five snipers at the airfield or Cherno/Elektro pointing a DMR at you at all times. Other than that, it's got no allure. Zombies are really just a nuisance, and it's amazingly easy to just plow them down with a car.
I mean yeah, to each their own, and if you like DayZ, that's fine. I just wouldn't buy ARMA II with the intention of DayZ being the only thing for it, because it's like buying Blockland for Slayer.