Deception is not sustained damage. Realize deception is meant for a 6-10 second encounter and for a quick and easy kill. You can't use surging charge without a stack? Terrible. Madness without the deathmarks that restore force? Terrible. I've parsed dps with 4-5 classes so far, and my friends have done all of them. Madness is among the lowest among our group of 5. Deception is near the bottom middle, and for darkness your damage reduction seems a bit off. It was extremely hard to keep me up when I was tanking scum & villainy.
This happens when people complain about a class. Vanguards/Powertechs destroy everybody when they run right tree dps, and nobody says a thing. An assassin runs a hybrid and gets a kill and people cry for nerfs. Huh?