I have mid-high end arms gear. I'm sticking it through because I got tired of watching cooldowns PvE and actually making breakthroughs in DPS weekly with very small endgame upgrades.
That being said, I don't reccomend PvP even under proper spec because simply put
- You are more CCable then most mobbs generally are in LK with only so many ways to break out and none on a short CD except fear (30 sec, and serves dual purpose to actually generate some rage.)
- Speaking of rage - many classes have damage reduction, and disc priests are bubble-aholics which means no rage for you.
- arms isn't bursty enough. If your target has any resiliance the odds are stacked heavily against your favor. Sudden Death executes are 7-ish K on a crit if you're lucky.
- Bladestorm off a hamstring sounds like a good idea...until you realize how many classes have solutions to it.
Against a target with light-to-no resiliance that isn't running though, it is pretty brutal.