Dayz performance wise is pretty much as good as its going to get. And it does take a powerful system to run.
DayZ isn't really frustrating because there is no expectation that you are going to keep anything you find. Eventually, no matter what, someone or something is gonna kill your ass, and its back to square one~
DayZ standalone will be going into Alpha soon on the updated Arma # engine, and will be highly modified and be more of the game envisioned. It won't have to work with the glitchy underperforming arma 2 engine.
http://dayzdev.tumblr.com/