Sorry to unearth my own old thread, but I've revisited the subject recently and just for grins and giggled bought a few of the '99 Bowie remasters done by Abbey Road Studios. I've now got three versions of Ziggy Stardust (Rykodisk, 30th Anniversary Edition, and the '99 EMI remaster) and two of Low (Rykodisk and '99 EMI remaster). I did a lot of listening to the 3 Ziggy Stardust CDs, and in the end I prefer the '99 EMI remaster. There are lots of instances of L-R channel mixing anomalies on the Rykodisk, and these are nicely reworked on the '99 EMI CD. Likewise, the '99 EMI Low CD sounds markedly better to me than the Rykodisk. In comparing the 30th Anniversary Edition and '99 EMI CDs, the track lengths are slightly different, but the mastering sounds nearly identical to me. I read a while back that there were some notable edits on the 30th Anniversary Edition CD, and that the left and right stereo channels were reversed, but this is definitely not true of the pressing I have... so much bogus information floating around out there.
I am a bit surprised to discover that I prefer the newer remasters to the Rykodisk CDs. I did expect for the '99 EMI remasters to be a lot louder, but I do not find much difference in that regard at all. Overall, I'm pleasantly satisfied with the overall clean, detailed and even-sounding music on the newer CDs. A comparison of just the first 10 seconds of Sound and Vision reveals a lot more impact, not just with volume alone, on the '99 EMI remaster. Switching back to the Rykodisk, it just sounds weak. The first 7 seconds of Speed of Life are enough for me to judge that the Rykodisk has a little bit too much treble, and sounds too "squishy" and soft at the same time. The (minor) volume differences are present in Subterraneans, but again I prefer the sound on the '99 EMI remaster. I find the overall sound better, beginning with the bass between the 14-16 second marks.
In closing, I don't think this is anything on the order of magnitude of a Rhino remastering of a Stooges or Doors album (I love the Rhino remasters of these!), but I do believe that sonically the '99 EMI remasters represent a step forward over the Rykodisks.