Hydra vs. ps600?

I am using 2 P600's to power 50 WPC Lab 47 Gaincard Amp, Sunfire Signature (subs),Forsell Transport, dCS Elgar/Purcell . While one is sufficient, I keep the digital in one 600 and then plug that 600 into the other along with the amps.The first 600 in the chain is run off a 220v 30amp line (balanced power) at the input and converts back to 117 at the output adding further gains. Quiet, Blacker background and more palpable images are main benefits. PS offers money back guarantee- I don't know about the Hydra.

I think I saw a Comparison from a user on audio asylum. You might want to check it out www.audioasylum.com.