I'll say "neutral". It means nothing to me. I would replace it with natural if anything.
What are the current useless terms in this "audio world"
Throughout the history of marketing of all kinds of consumer goods there have been many useless, hyperbole phrases and words used. It seems on ebay, here, craigslist and others a current pet of Sellers is taking something to "the next level".... which sounds like a great marketing term for an elevator maker.