I just go by my ears. Tbh I never had my system without power conditioners and audiophile power cords until now. If anyone wants to go by lowest scientifically measurable noise in electricity, he should buy the Trinity power conditioner like I did. I spent something like $30,000 for that. Go look at Trinity thread in AE forum and you can find all the measurements. I dont suggest everyone to not use what they have. I suggested only Christian to try since his moving will already involve a big change and the connect/disconnecting of gears. And also because he has the ultimate front that let you hear any thing that changesdown the line.
Tang
Sorry to disagree, but if someone wants to buy a power conditioner using science he needs a lot more information than the few plots selected for marketing by audio manufacturers. There is no unique ideal power conditioner. Even if we want to carry the selection based on technical parameters , before taking any decision we must analyze our mains with some care and depth and look at the technical requirements of our systems.
And then we have the subjective evaluation, something that must carried with time, and where many surprises can happen. It is not possible to have rules, our preferences are too variable.
BTW, science is of little help in most of these power conditioning matters. In order to apply science to solve a problem you must be able to define it clearly and have a model of the interactions between the parts involved. As far as I know such thing does not exist in hour hobby.