I also use Furman power conditioners and they seem to help keep the noise away. I have not noticed any degradation in sound quality, but if there is any lessening of sound quality it is far less than a small tweak, like upgrading a fuse in one of your components.
Now that I've added my two cents, I have a question as to where do you place your power conditioners? I am very space limited and I wonder if I can place one of my components right on top of, or set the conditioner on top of a component. Would there be some type of shielding I could use in between them? My only other alternative would be to place the Furman on the floor, behind my components, where I wouldn't be able to reach it; so it would have to stay perpetually turned on.