I've yet to experience any deterioration of the ones I've created with a Tascam CD-RW700, but it wouldn't surprise me. Have done my share of sharpie-writing, to compound the problem. Time to knock wood, I guess. BTW, the Teac machines DO require special "audio" CDRs, but the Tascams don't.
Finally, I've never heard a computer-generated CDR that sounds as good as the ones the Tascam produces, and Lord knows I've tried. Dave