Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Ridata BDR-254-RDCB15 4X BD-R discs

These single-layer BD-R discs work fine with my LG WH10LS30 internal BluRay burner, with the exception that they burn at only 2x rather than 4X as advertised, which means that it takes about 40-45 minutes to complete a disc, not 20-25. But that may be due to a problem with my system (or the burner), not the discs. The only BD-Rs I've tried (so far) that burn at 4X are non-LTH Verbatim BD-Rs (the LTH versions burn at only 2X) but they're considerably more expensive, though just as good. Regardless, out of about 40-50 Ridata discs burned so far I've yet to get a coaster. Very good quality at a reasonable price.