I would recommend only using high quality Taiyou Yuden brand CD-R's, that is all I use for my back-ups, now. The PCE family of CD-ROM2 systems are not as picky as my JP MCD1 systems, but I notice no difference between originals and said back-ups, unlike cheap CD-Rs I used in the past. I had problems getting TDK and Verbatim discs to load on the MCD systems, but TY discs play perfectly.
In regards to the SCD, is it wise to invest in a gear for it? I have seen them for sale but had no idea if they are a big problem like the CD-ROM2's Middle gear.