Who uses power conditioning?

Furman Elite.

I don't notice it until it is gone.

No way I'd put my gear straight into the wall, but I come from a state with notorious bad thunderstorms and lightning.  Also, I've never heard the Furman make things worse, only better.

I use differential noise reducing component before my eqitech 2q. Experimenting confirmed this works best in my system. Am curious to try filtering the grounding after reading about shunyata ground filter used in the absolute sound ref system. Has anyone experience with the ground filter?

Always had good results with using balanced power products compared to other types of power conditioners. Have used BPT, Blue Circle, Bryston (rebadged Torus), Equitech, and now Plixir, and they have all gave bigger improvements than other brands that don't do balanced power. 

Everyone's house and system is different but that's been my experience.