I guess I didn't make myself clear
When my friend got interested in power conditioners I got him a Sola because it was available to me at a friendly surplus place , essentially for free , which was generally the correct amount to invest in my friends case. He was using fairly decent amplflyers. I didn't want him to go out and dump a bunch of money on a moronic audiophile power conditioner.
The nice thing about Sola's is they have voltage regulation (although they need to be sized correctly for that to work correctly)
I believe I pointed out that they need to be sized correctly. If yours were putting out lots of heat maybe they weren't sized correctly. They are only supposed to dissipate a small amount of power. Maybe your feed was such that you really really needed them. I never had a problem with them running very hot. Particularly when compared to tube equipment (not just audio gear) or class A audio amps.
If a piece of equipment has power supply problems then it doesn't belong in my system. You don't need an isolation transformer to get rid of ground loops. If grounding chasis's and permutating plugs won't clear up the problem then some engineer didn't do his job correctly and I don't want gear like that. You should not have to add an isolation transformer for everything. (disclosure: I do not participate in headphone audio although that could change in the future)
I have always told anyone willing to listen that the whole power conditioning thing is in the same category as cables. If you believe in that stuff I have no interest in disturbing anyones' enjoyment. But if your gears power supply is so poorly designed that one of those things actually helps , then the correct action is to get better gear , not get a power conditioner.
All that said I think in this modern day and age it is very important to have lots and lots of surge protection to protect our everincreasingly computer operated lives. This became clear to me maybe ten years ago, when a pal of mine asked me to look at his wife's "Kenmore Elite" washing machine.
This machine was actually almost a thing of beauty. It had a gorgeous stainless steel tub and they had paid $1000 plus for it and a similar amount
for the matching dryer. His wife was a workaholic and only bought the best of everything. She had two Lexus (Lexi?) When I go there I discovered the computer system that operates the whole washer had developed what I call Alzheimers disease. That is the control panel would light up but in spite of every known trick attempted and resets performed it would not take key strokes on the buttons. Diagnosis: sick , unrepairable computer control board. Treatment: Replace same. Then there followed a bunch of arm twisting to sears to furnish the part for a reasonable price since the unit was just out of warranty.
After it was repaired I told my friend that the washer and dryer needed to be on a surge protector and that the whole house probably ought to be on one.
I don't know if a surge caused the problem. One think if many other problems ( It was probably an early example of RoHS circuit boards for example).
But I do recommend to friends overdoing surge protection and do so myself. There is no downside except a cost which is generally modest compared to the equipment protected. In the above example Sears wanted like $500 for the repair. We did get the price down but it took some application of guilt till we found someone who was susceptible to that strategy. Maybe that is why Sears is gone now.