I had forgotten about this post. I've since borrowed from a dealer some power conditioning to try. I brought home a 6 outlet isolator and cleaner. I thought this would do great things. I also brought home some power cords which I thought would do absolutely nothing. All of this was Transparent. Well to my surprise the isolator had an effect but I didn't like what it done. It seemed to have a negative effect on the sound. However, I was estatic with the results of the power cords. As Laps said, it was a welcomed dramatic upgrade, the background was quieter and everything sounded more natural. I put one on every piece of equipment that would allow the upgrade. The largest leap of improvement was noticed when I put one on my phono preamp, amazing. I can't explain why it works but it definitely did for me.

I am surprised you noticed a difference between PS Audio and Shunyata, I haven't used either but I think of PS Audio as the pioneers and fore runners of this technology. I have heard results may vary from brand to brand depending on your particular power company, how the house is wired, what interference is around etc. Some brands deal with certain problems better than others.