This is good news (since the Virgin remasters of Bowie's back catalogue sound better, to my ears, than the older Ryko masters) and bad news (since much of the material on the box set consists of songs already found on the various album remasters). I'd prefer them to just issue a one- or two-CD release with all the non-album rarities.
But... there's enough good material on S+V for me to justify picking up the re-issue even if it does have tracks repeated from the albums. The demo of "Space Oddity," the acoustic B-side version of "Wild-Eyed Boy From Freecloud," an otherwise-unreleased gem called "London Bye Ta-Ta," the original "1984/Dodo" track from the Diamond Dogs sessions, the single version of "Rebel Rebel," the Young Americans outtakes "After Today" and "It's So Hard To Be a Saint in the City" (a Springsteen cover!)... yeah, I think I can handle getting improved remasters of these songs, 13 years after I last bought them.
(Completism is a disease, folks.)