Hang on a minute. Of course, later stuff like vol 2 is likely to be recorded on better gear and perhaps had better mastering. She was a bigger act when that later stuff was recorded.
On the other hand, some mono jazz recording from the late '50's sound fantastic.
All that modern equipment isn't helping with much today is it?...modern mastering has taken what advantages the modern equipment had and negated it....the first version Gos posted was mastered by Doug Sax...I have that CD and it is better than a LOT of stereo SACDs I own....maybe Gos will comment on how good the first version was in his opinion...