Who Tried Power Conditioners Over The Years and No Longer Use Them Today, Any Why?

"Ignorance is bliss."

in a nutshell, unless your CERTAIN your power feed's voltage is a +/- under 5% 120VAC, I urge you to consider a conditioner w/voltage regulation. My APC H15 SAVED my previous pre/pro from my former* home's electrical system. Further I believe the H15 doing the same for my (Same brand) current pre/pro.
*rental on a grid close to a lot of businesses & a junior college.

Even today** I witness the "Trim***" LED frequently light up on the H15 for several hours at a stretch several times a week. Because of "compromised" hearing****, I won't swear it "greatly improved" the SQ, but I'm VERY confident it's protecting my system's delicate microprocessor-containing components from the above and the brief effects from AC, freezer, & refrigerator etc startups.

**4 1/2 years in a rual neighborhood. 
***circuitry activated when the line voltage exceeds 132VAC

****unprotected on tank ranges; 10th row seating at concerts; extended listening to insanely powered car audio systems - all when I was young & stupid 

Your system's electrical "sweet spot" is 120VAC +/- 5V. Continue "Unprotected" at your peril.

Tony  

High end power cords? I wholeheartedly agree, heavier is better. Beyond that; maybe, but... Read my "compromised hearing" explanation from my previous reply. 
 

I recall from another forum a member having "ah hah moment" from, he claimed,  bass response from upgrading from the stock removable 18 ga to an inexpensive 14 ga upgrade.  I plan to mod what gear I can to take advantage of this inexpensive, undeniable upgrade. Currently, of my system's 11 amps & subs only one of them has a removable PC. That 230VAC sub came to me needing some surgery to make it work. While I was at it was easy enough to install the EIC not to mention a generic 4' PC. 
 

My add'l $0.02

Tony