"Devouring Swarm (morph of Bat Swarm): Reduced the healing on this ability by 30%."
I could do ok with my 2-handed stamina build because I had this one ultimate. I hear it is op for magicka builds but it made it so I at least had a chance. Many times I had to re-clear chaff and rebuild up ultimate just to be able to try an 1 or 2 elite at level. I never feed because 30 min is silly especially when in a group so I'm always at level 4. The ultimate made this ok, now I don't think stamina vamp is viable for me at least.
I bet it is a tough job to try and balance a game. This one spell seems to make some builds op while others just powerful enough.