There has been lots of discussions about U.S. and Japanese RVGs on the Blue Note bulletin board:
http://www.bluenote.com/bulletinboar...Ultimatebb.cgi
Opinions are divided. What is generally agreed upon is that the recording levels on the RVGs are significantly higher than previous CD versions (remastered usually by Ron McMaster) - some may be too high, according to some reports.
My experience is mixed. And I have too many McMastered recordings to replace, even if my experience with the RVGs was uniformly positive.
My two most recent RVG purchases were of recordings that I had previous CD versions of. I bought the Japanese RVG version of Jackie McLean's "Demon's Dance ". Japanese RVGs come in cardboard sleeves that duplicate, in miniature, the original record jackets. Pretty nostalgic, but I prefer jewel boxes, because sliding a CD in and out of those sleeves inevitably scratches it. Compared to the McMastered version, the Japanese RVG is significantly louder (so I equalized the volume when I made other comparisons), but the separation is reduced. Trumpet and saxophone come more from the middle, rather than from different speakers, as on the McMastered version and my recollection of the original LP. The piano is a bit clearer on the Japanese RVG. I'm keeping the McMastered "Demon's Dance" and someone's got a holiday gift.
I am keeping the American RVG reissue of Wayne Shorter's "Speak No Evil", however. The separation is not as compressed as the Japanese "Demon's Dance" RVG, relative to the McMastered and LP versions. Also the overall sound is a little bit clearer, and there's an extra track.
In my opinion, one should not assume that the new RVGs are better. It varies by the recording and personal preference. Rudy Van Gelder is a terrific engineer, but not always as skilled in remixing.
Also differences are sometimes reported between RVGs from Japan and the United States. However, those reported differences have not been consistent either.