I don't necessarily agree with that statement; it's not just VAs, but I think is related to "circuit" design. Every power conditioner I've had in my system has had a NEGATIVE impact on the sound (except for one, as mentioned, the PS Audio P300) and reduced dynamics is one thing I have noticed repeatedly. Mind you, this isn't llike the system lost power, per se; but that the dynamic difference between loud and soft shadings is less than normal, lending a more compressed feel to the music. I don't think this is necessaily a lack of current... Those P300s don't put out much current, anyway.
I do think a good power conditioner should just do it's job without calling attention to itself in a negative way--and from what I've heard from folks, I need to try some of the newer designs. I think the old school "filter" designs could really be the issue.
I still don't understand how the Furutech works, but hell, if it helps...