I could never tell worth a crap when something had really been "fixed" with remastering--probably only The Who's My Generation double-disc reissue which nonetheless offended people anyway, because it remixed the album into Stereo, which resulted in overdubs on certain songs being lost, like "Circles" now doesn't have Entwistle's freakin' horn on it!!!
John Mellencamp said that CDs were an excuse to make people buy their record collections a second time. I double dipped only a few times, really. One was for Steely Dan's Can't Buy A Thrill b/c the new liner notes were just that funny.