I've tried a Cinepro powerpro 20 and a Shunyata Hydra. Both are good, the Hydra has a blacker background, better dynamics and detail (for twice the money used). FYI, I have a vk50se and I kept the Hydra.
Powercords can change it big to. I like the Fim Gold, Transparent Ref xl, and the Kimber palladian 10 the best.
Finally, dedicated 20amp circuits are a must. Big step up for the money IMO.