Here's my two cents: Well, I have it. . . and I listen to it. I find it fascinating to listen to a few cds worth of these at a time. You get into a sort of bleak world with spotlights here and there. Great music, makes you sad to remember the Billie of the thirties and early forties, but she still can knock you over in these recordings. . . .
You may well just sit tight where you are. It's probably fine to grab the individual releases here and there now and then. But the box is a worthwhile purchase, especially if you can get it from one of the clubs or used at a good price. I find that the sound is good and holds up. . . .