Now that's an interesting statement, "why use it if you don't need it?" And, I agree with the notion prescribed. It depends on your electrical enviroment as a whole, i.e. one set of problems may persist at one location but not occur at another. This boils down to the power companies service to your area. If you live in an industrial part of town with lots of equipment bleeding grunge into the line that's one thing. Or, maybe as you stated, there are voltage problems. These are two different things and require different approaches to begin with. On the other hand many modern day circuits seem to have all kinds of junk going on, and few of us are exempt. There was a bige difference when I lived in Tucson North side compared to Tucson downtown. I have ended up considering some kind of power conditioning in most places that I have lived. Again, the prescription must serve the need/prognosis.