My Experiences With The iFi Power Station
So there's TONS of info in the history of this thread, so I won't bore you with regurgitation of "same-old".
Do I think it's worth it? - Yes. Particularly if you have noisy wall or wifi devices on the circuit or nearby.
Do I know it works? - Yes. We have an old off-branded wireless phone that my wife had in her flat that came with her in the move/consolidation of our things. (It's RED, her sole qualifier for an electronic device before we met.) It's so bad, that I regularly use it and an old blender to simulate radio and line noise respectively in the testing of all electronic/power devices I investigate. NO NEGATIVE EFFECT on audio when played from my sensitive tablet or laptop when used in close proximity of the powerstrip (2-3foot area from iFi strip tested) when both were turned on. Squeals, hums, pops, & clicks can be heard just above the noise floor with the volume up otherwise.
Is the Ground & Polarity diagnostic "real"? - Yes. In my server room, the power is pristine behind power conditioners and battery backups with diagnostics. However, when I hooked up the Power Station out on our patio, I was able to find that a mains socket that I had ear-marked for eventual upgrade failed the ground test (Which I already suspected had a fault) and when I slipped-on a ground-bypass adapter without the wider prong and plugged it in backward, the iFi's polarity LED immediately turned RED.
Do I report "vast improvements in sound quality" when I added the iFi Power Station to my audio chain?- No. As I mentioned earlier the power in my server room (Where my audio stack also happens to be.) is already quite good. However, the power strip offers passive noise cancellation of ambient noise from external devices like Wifi routers, cell phones, CB radio, etc.. that share the space from interfering with the sound that my components and headphone cables conduct. To me, that's a definite advantage.