I am doing exactly the same thing as you. Operation Dummy + MoX Parser and was getting 1060 dps over a 3-5minute period. I tried both Deception and Madness and could not see any difference. I am 4/5 Rakata, Rakata OH, Rakata MH mods in a orange critted DBLS, Orange belt, columi bracer, rakata implants / ear, energy Proc relic from HM's and matrix cube. So I am not undergeared and There is no way I saw 1500, except for the initial start on the Dummy which does not count.
Please share your secrets.