Very interesting because these days the normal thinking in the audio world - straight to wall is best period, and power conditioning will limit, and even compress sound with most components.
This has been in fact my results overall with most power products period claiming parallel, or passive, or active filtering regardless.
Most of the time straight to wall proved best.
ACCEPT - when I accidentally found, and acquired a fairly expensive power strip which was retailed at 1000.00 a couple years ago for a pretty cheap price that was intended for a basic power setup in my NON-high end system.
Well I decided to try it in my High end setup, and it beat the pants off a Walker Audio, and even direct to wall! First time I heard conditioning, and surge protection at its best.
Its an IsoTek EVO 3 Sirius power strip which claims to simply have a quality filter with upper echelon teflon copper star wiring basically. Well it works. I have had many power bars, but this one will put huge regenerators, power conditioners etc... to shame. I don't even think they make them anymore.
For that price originally its very arguable that they went a little to skimpy on the outlets themselves in quality, no super grip furutechs, or even decent hubbles in here, but they work well. Interestingly I also noted they designed these 6 outlets right compared to other Richard Gray and higher products I have had in the past because the spacing is much better for larger wall warts etc... that we sometimes can't avoid. They all fit on it very easily if necessary to use unlike all the duplex based units on the market.
Only slight downfall to a quality device like this is even though it carries 6 outlets, its only rated at 10 amps, which it does have a FUSE in it, and I upgraded that to a Synergistic RED fuse, and I actually paid nearly as much for the damn fuse as what I stole this whole unit at originally! But it was worth it.
I don't run big amps or anything thru most power distribution devices, so in the case of something like the IsoTek bar 10 amps was actually over double what the rest of my system pulls in total anyway.
I still don't advocate power conditioning in general, but this is one of the very few cases a device like this actually shows all the advantages to not only conditioning, but getting the protection on the circuit. http://www.tonepublications.com/review/isotek-evo-3-sirius/
Only other one I can recommend is simply the "Bybee AC bullet" which is a decent upgrade for many systems. Its not conditioning per say, but from most of the uses I have experienced it has some positive merit on most systems AC lines. http://www.partsconnexion.com/bybee_bullet.html
I have owned several units from PS audio, Balanced audio, Blue Circle Audio, Walker Audio, Furutech, Furman, ATI, Richard Gray, Shunyata, and IsoTek. Never run amps thru anything in my opinion unless it's a single dedicated filter possibly.