I'm very happy with the Virtual Dynamics Nite P/c that I have on my HC UO.
This would not be a good solution for everyone, but in my system, I don't use a power cord to feed my UO!
I have a dedicated line (12-2 w/ gnd) coming from the breaker panel to a junction box in my crawl space directly under my gear. I split it into two feeds coming out of the junction box, and bring them up through the floor under my equiment rack, and I terminated them with Marinco IEC connectors. I plug one directly in to an UO, and the other into a P300 Power Plant. The UO powers my Martin Logan electrostatic speakers, and the P300 feeds my source and pre-amp. I have another line (10-2 w/ gnd) that I brought in directly, and terminated with a Schurter 20 amp IEC that feeds my power amp.
As I said above, I would not recommend this to everyone. Obviously, if you rent, it's probably not a good idea. In addition, since you probably won't be able to talk an electrician into doing this for you, you will need to be confident in your ability to do it without either electrocuting yourself, blowing up your connected equipment, or burning down your house. That said, it provides ultimate simplicity, and reduces the number of connections in the path, which by definition reduces the possibility of having faulty connections (if done correctly).
On the other hand, you could probably pick up a 1 meter original PS Audio Lab cable pretty cheaply, and I would think that would work quite well.
I use the Virtual Image Sledgehammer and the Pile Driver PC's. I personally have never used the PS Audio UO, but I was told by a friend that it really muddies up the bottom end, though I did notice this effect with a PS Audio Juice Bar. I would recommend upgrading your power cables and doing an A-B with and without the UO. Anyway, if you are interested in trying the Virtual Image, Contact them at email@example.com , they offer 30-day money back trial period. If you decide to try the V.I. Pile Driver, they seem to need some burn-in time, where as the Sledgehammer doesn't seem to need any. These are the cables that I replaced Ensemble Megaflux PC's with. Please feel free to e-mail me if I can be of anymore help. Zach