i played deception at first....religiously. I know personally it was frustrating to get a maul off, because of lag. My sin would wind up, on my screen being right behind them, and tada, i would stop my animation halfway thru, and get error msg. hit it again, no go, same thing.
Basically lag/latency was messing me up. this was a constant thing.
Then i went madness. Madness seems more squishy then my deception spec, but i will never go back, as the lag/latency doesn't affect madness nearly as much. I think if you were sitting next to the server or down the block, you'd rule as deception. Otherwise, it stinks like doo doo.
Darkness, when i tried it, was just insane. i couldn't believe how fun it was.