Power generator or Power Conditioner?

https://www.stereophile.com/content/analog-corner-315-electrical-cure along with preceding stereophile reviews appears to tell a story supporting jsalerno's "voting rules".    

My question:  (perhaps answered elsewhere previously?).   What tool if any will help one determine if "Mains supply is inconsistent... or home circuit is subject to inconsistent voltage...."?   

I use the Synergistic Research PowerCell UEF SE to power all my equipment including my amplifier. It is an older model, but seems to do the job quite well.

Nice to hear!   I have further looked at my electrical situation from my 20 amp non dedicated outlet using a PS Audio Powerplant 20 (PS 20):  

      My input voltage on this PS20 reads anywhere from 120.3V to 122.3V.

     The output voltage (going to my system) on this PS20 is consistent:   119.5V

     Current pull (amps) from the outlet varies from 1.7 amps to over 3 amps depending on volume, and whether playing two channel or home theater...

??Any thoughts from the group whether I would benefit more from a power conditioner than this PS20??     (yes I reckon there is only one way to find out)

What do your distortion numbers and incoming sine wave look like on the P20 scope? It sounds like you have pretty stable voltage, maybe all you need is a good conditioner. I think that @jsalerno277 gave a really good answer, but in the end it is really trial and error with different products. 

Hi zlone (et al)--   to answer your questions:  

---my incoming (from the outlet to the P20) distortion tends to be around 2 percent

---outgoing distortion (from P20 to my system components) currently shows.  0.1 percent.  

---the incoming sine wave-- looks a bit jagged on the top and bottom (not sure how to read it) with the outgoing sine all the more rounded on top and bottom.

For distortion in general-- I have found the "low distortion" setting perhaps that much more clear for center channel dialogue than the "high distortion" setting.

Any additional thoughts?