It's anecdotal, but on the Infernal Council fight, the annihilation marauder from my standard hard mode group and I (madness) both take on a 49k hp mob. Since it's a solo fight that begins at the same time for both of us, I feel like it's a pretty good dps race comparison. I routinely kill my council member before he does. He's got insane burst and great sustained dps, but on a 1+ minute fight I pull ahead with dots. Typically I'm done first, then him, then a toss up between the other dps. The poor sniper always needs help; it's not a kind fight for him.
My gut feeling is that Madness dps outshines Deception. I definitely feel the difference in operations, where mob hp is higher and fights last a little longer. Once you get a feel for the spec and how to properly hang your dots, it all comes together and makes for a really fun and unique class experience. Deception is just a WoW port, sad to say. I leveled with it, but I don't really feel like it's raid viable compared to Madness. The utility it gives you such as faster stealth movement just isn't helpful on an operation, and your range limitations become a major liability.
If anyone needs help, it's Deception. Madness is fine. Honestly, Deception could go a long way just by having someone take a close look at Static Charges. It's pretty clear that they're just a stand in for combo points. Build 5, hit stuff hard. It's awfully simple. The problem is that there aren't enough ways to build them.