starfox_2100 doesn't really have a big problem like burning coasters..I'm sure the scans would be very good if he cares to post them
It's only that he cannot burn faster than the certified speed of 4X with the Ridisc which are not exactly cheapo media although they are pretty cheap in price.
In fact, the Benq doesn't let you burn most -R 4X media faster than certified, including Verbatim 01RG20, Taiyo Yuden G01 whereas +R 4X like Ricoh R01 are burnt 8X with very good results. Only Taiyo Yuden G02 -R 8X can be overspeeded up tu 16X.
In this sense, the drive has more capabilities with +R and it burns decent -R 4X media slower but with good quality.