On single target, I use it every single chance I can get.
I'd say there are six pros and three cons to this skill.
Pros
-Fast animation to deliver damage quickly
-Low TP cost actually makes you recover 20 TP after regeneration
-More damage than Savage Blade
-If you can use it consistently, the total damage output is better than just the standard Halone combo
-If timed properly, can be used as an interrupt to melee red aoe skills
-Does not cancel the Halone combo meaning it's meant to be used while the Halone combo is active (can get off 2 shield swipes in a row before reaching the limit to the combo expiring)
Cons
-Requires a block
-Low aggro buildup
-Window of use is only around 3 seconds