Yah, this might be a little late...
I used to have the Powerbar which has 3 PowerPorts if I remember correctly. I also have a single PorterPort in the wall with an Audio Magic Stealth Mini connected to it. I can't directly compare the two since the two ports are used in different ways, one being a wall outlet and the other in the Powerbar. However, as my system progressed, the Powerbar sticked out as a sore thumb as the weakest link. After I went with the PorterPorts and AudioMagic, I feel my taming of the bad AC is sufficed for now.
The difference between before and after is that with the Powerbar my system sounded chalky in the mids. After the PorterPorts, out goes the Powerbar and before the Stealth, the system sounds much more clear. I also chopped off a bit of wire that was in the wall and looked a bit corroded. So, that is a contributing factor as well.
The Stealth added a bit more detail and finesse to da system.
Hope this helps whoever else this helps.