I used a PPP for several years, but I found it tended to be overtaxed by power amps. Owners who used them for amps reported more reliability problems. I used it for sources only.
For sound as well as robustness under all conceivable loads, as well as lower cost, the Pi Audio Uberbuss works very well indeed with my ST-10. Improves the soundstage notably, even a bit more than the PS Audio.