Thanks for the input, guys. It's kinda scary to know that Super CD-ROM2's also have issues. Or at least the three discussed here have had issues. I actually have a US region-switch-modded TurboDuo that had its sound completely go out. I replaced every single capacitor but 4 I couldn't get to easily and the sound came back about 90%. But the CD sound still cuts out after a while. I have a SuperGrafx 'laying around' so I figured I'd region-mod that and get a Super CD-ROM2 and an Arcade Card and be able to play anything I wanted from JPN or US in any format. But finding a (working) Super CD-ROM2 has proven a bit harder than I imagined.
I've also considered a Duo-R/Duo-RX, but that would still leave my SuperGrafx in the box in the closet as I only have 2 SGFX games anyway... and they're not even the good ones. I don't have 1941 or the Ghouls n Ghosts games. Curiously I do have 1 Arcade CD-ROM, but no Arcade Card either.
Anyway, I guess I'll still keep holding out for a working Super-CDROM2. Then I'll region-mod my SuperGrafx.
Soo... bump again!