I don't think you can ignore either the room or the electrical power. My preference, in both contexts, would be as little 'treatment' as possible. In the context of a room, I mean a room that sounds good in the first place. Granted, those are rare, and yes, you probably do have to do some degree of diffusion, absorption, take account of reflections- but I remember the room i had two houses ago- 110 year old heavy real plaster over lathe (horsehair, i think, behind that), heavy wide beam floors, high ceilings, great dimensions. That room just sounded fab. My current room is all odd angles, not really big enough in any dimension, and I have the fully panoply of corner bass treatments, diffusion and absorption panels. Ideally, my next room will be purpose built and I will have to do a little, but not a lot of 'treatment' to get it right. I'd like it to be 'right' in the first place to the fullest extent possible.
AC power- I've tried a few conditioners (not the latest crop) and other than doing a dedicated subpanel and dedicated lines with hospital grade receptacles, proper phase, etc. I don't use any and go straight into the wall. No power conditioning. I bought a big Equi=Tech wall cabinet for my next room, and I hope that's all I'll need to keep the vagaries of AC power to a minimum.
So, I guess where I come out is- Franz and Myles are talking about two things that are both important- but that in an ideal scratch- built listening environment, less may be more?
As a footnote, I will post in a separate thread regarding another 'tweak' I'm playing with that does not directly bear on either power conditioning or room treatment, but more philosphically, relates to the overall sound of the system and its 'tuning.'