benchmark for quality of DVD/CD disks
 

As I have encountered difficulty in viewing some of my burned DVD disks, I used Nero's CD-DVD SPEED utility to check the quality of my DVD disks. Among other tests, it maps the disk and shows the speed of reading at each of the disk's sectors.
It came out that disks that play nicely at my DVD player got good marks by Nero's CD- SPEED utility, and DVD disks that worked badly (stammering or even stopping at the middle of the show) -in these disks one could find many sectors labeled as damaged or bad.
Can any one direct me to a link where I can find quality comparison of various DVD media brands?
THANKS.