Hello Ptss.
I do not recall which conditioner I tested. The improvement of the conditioner ($4000) was so small, compared to the transformer, that I lost interest in testing more conditioners. I just went with more of what I had - transformers.
If you want to go more exotic than isolation transformers, you could add an industrial constant voltage transformer afterwards - but the returns are diminishing very rapidly at that point. And some of them are VERY noisy. Better to upgrade your caps, resistors, and rectifiers.