Regardless of what's in a power conditioner and what it costs, I'm very suspicious about manufacturer's claims about how good it is, yet don't bother to give you any filter curves, Joule capacity, bandwidth, etc. Clearly, for low cost units, you aren't going to get a lot of data because it's doubtful any verifiable tests were done. But, for the big ticket boys, it's inexcusable not too publish their attenuation, isolation, surge capacity, and bandwidth specs.
I don't care what folks say about a given component, I'm not spending my money on a black box made with secret sauce with claims of wonder and amazement. Line filtering is not an art form, it's pure science. So if a manufacturer is being secretive, I'm very suspicious.

