I have the Panamax MAX 5100. We have no problem with dirty power here and so I really can't tell the difference with or without. I like the 2 high current outlets and the fact I can turn on my amps with a 12vdc trigger, and have them power up on a 10 second delay.
There are other outlets that will follow the trigger too. I use that for my cooling fans and power to my 7" LCD monitor I use to search the menus on DVD-A so I don't have to power up the Sammy DLP.
Check
Here for the best pricing around.