I agree. Between all BLoSC villans he's the most threatening.
In my opinion he's ten-times better than Zurg: he's smart, ruthless, clever, powerfull, scary and terrifying; he knows how to become your worst nightmare and he doesn't lose himself in pontless drammatics like Zurg does.
At the start he was ambitious for power because he was programmed to, but then he decided to just satisfy his hunger for energy and revenge. First he was one of Zurg's minions but then he became indipendent and worked for no one but himself. That made him even more respectfull.