Kocho, is the dye material used at all a significant factor (from cynine to phthalocyanine sp?, etc.). I've heard that the better CD-R's take the laser info more cleanly since it is a "physcial" process, regardless of the accuracy of the machines at hand. A hypothetical analogy would be if we had some cutting tool, but the materials we are cutting are different (the different dyes), then the resulting cuts on each piece could be different. I.e. a conventional power saw running through wood will cut much differently than if we tried to cut glass with it, even though the saw factors are all same. I don't mean to make an unscientific analogy that holds no worth to it, like the infamous "running through a forest" one and loudspeaker cables. Personnaly, I've had no problems with my CD-R's and think they sound quite fine.
