Vampire ulti - which one for PVP

Homm

Heya. I always played with devouring, never cared enough to change it. Many pple told me clouding is so op "cause u can't get stunned/knocked etc!". Now, with cheap respec i changed it and.. disappointment. I feel like devouring was way better. Sure, with clouding I can't get kicked in the balls, but who cares on knocking down a vamp when he's casting? Impulse the *** out of him and he's dead. With devouring+crit surge I felt immortal, even on the ground, while the ulti lasted. Well, at least for group vs group it was true.
I think I should try clouding for a little longer before I make a decision, but for now I'm not impressed. What's you thoughts on this? Which one do you prefer on PVP and why?

Btw - I'm a sorc (as crit surge suggested). Also, please don't point out PVE, it's a different story.

BugCollector

Devouring is better than Clouding. and you can even achieve both ulti's if you've chosen Devouring. Hit Devouring swarm and then Mist Form and mission accomplished.