I compared the Powercell to a Runing Springs Haley and to a Modified PS Audio P-300. The Powercell is more dimensional than the Haley and has better instrument separation. Tonal quality is about the same. I use the Haley with a Purist Limited Edition powercord to the wall, which really takes out high frequency glare, but overall, I prefer the Powercell because of the more realistic dimensionality. I have not used the Purist LE to the Powercell because of the Neutric connector, but would sure like to try it.
The power to the sheilding on the cord, I can do without. Power to the internal shield inside the Powercell is preferrable; a little more weight and dimension.
I did not like the P-300 plugged into the Powercell. Weight and dynamics were lessened, and the tone was slightly uptilted. No other power conditioner aside from an earlier P-600, has improved the P-300, and that includes the Primere from PS Audio.
For the CD player, I preferred my P-300 over the Powercell, but only by a small amount. My P-300 is quite modified, and I use a Purist Dominus Fluid to the wall. It is clearer and more defined, but a tad "steelier" than the Powercell. The steeliness could be the P-300 or something else in the chain, most likely the CD player.
The Powercell also improves the entire range with tubed equipment, based on my headphone amp and preamp, both with vacuum tubes.