This is one of the game's best weapons. Yeah it's quite slow, but when you use your War-Cry haste skill, it gets much better. With such a high agility bonus, and the bonuses to criting, you become a crit machine. The tactical crit bonus helps you to crit your shouts, and the 5% chance to drain your opponent's power is the additional 5% on top of the 5% you already get from the first description. So, roughly every 10 strikes, you drain power from your foe. :)
If you slot the class traits Expert Attacks (+1200 Devastaing Blow/Pressing Attack Critical Rating) and Captain of War (increased attack speed with the use of War-Cry,) you can do some serious damage. Throw down the Banner of War for an extra +50 Might and Agility...and the power is intoxicating. :) Critical hits, even when you don't have much might, are up in the 900 range on lesser/equal mobs in the low 50's lvls.