Despite some poor reviews, I've had 100% success with these discs. They were recorded on a cheap PC DVD recorder, and then all played back perfectly on a mega-expensive, mega-fussy Toshiba player. Out of a spindle of 25 discs, I achieved 25 perfect recordings which is better than any other discs I have used. I've no idea if it helps, but I always record at half the stated speed of the discs - hence the above results were had by recording at x8, rather than x16.
I think that judging the performance of media such as this is very difficult to do objectively. My personal experience is that often the media is blamed when the real problem lies with a faulty DVD writer.