A CD-R is going to work better because most CD-Rs are not made in China, but in Japan (extremely strict quality control) or Mexico (under supervision by a company in the USA, so again, extremely strict quality control). Sad, really.
And if anyone actually says that "padding the image so it fills the whole CD makes it more reliable" then you need to shoot them in the face with a bazooka. Ugh... the stupid, it burns...
If I ever make a Sega CD game (don't count on it... I can't stand the graphics limitations, I'd rather do a Dreamcast game), I'd at least have it pressed domestically.