The production quality problem is entirely the fault of the RCA label, you'll notice the same muddy sounding mastering on all the early Scorpions work, too. I think they were still mastering albums on equipment from the early 50s until the end of the 70s. You can't even remaster it digitally now and make it sound good.
I've heard some of Bowie's 90s work (The Heart's Filthy Lesson comes to mind), but nothing that really impressed me, though I had pretty much given up on him by the mid 80s - Lets Dance just didn't do a thing for me, nor Tonight, with the one exception of Blue Jean. I did, however really like Tin Machine 2, so go figure. I guess technically, that was 90s work, as it came out in '91.
Of course, other than Ziggy Stardust, he was always one of those performers I preferred to take in small doses. He has songs I absolutely love, but 40+ minutes of Bowie in one sitting is more than I'm usually up for.
OTOH, I can listen to Kate Bush all day and I know a lot of people who can't sit through one song without complaining.