In terms of sound and interface, it worked the same as it does on WinAmp. It worked "ok" with WMP, though not as stable as it is with WinAmp. WMP would sometimes get its "I've had a problem and disabled all plugins" states. I'm guessing the problem was WMP updates that Ozone didn't keep up with, it worked better on the earlier WMP versions. Most recent WMP I've used it on was WMP11, it ran ok but the "disabled plugins" error was somewhat common.
I quit using WMP altogether a couple of years ago. Had to start it up just now to see what version I'd used, it was 11. Loading up your music directories in WMP can screw up your album art in WinAmp. WMP creates its little art thumbnail files in the directories and points the music files to them, then WinAmp's album art looks horrible (enlarged small images). Fixing it within WinAmp wasn't as easy as you'd think, not sure that I ever really figured out a way to do it. Could be some WMP setting, don't know, but I got tired of it, reloaded my music files to the hard drive from scratch (pre-WMP thrashing), and kept WMP out of it.