Question about DL media and 2014S1T

[qanda]This thread is about the Asus DRW-2014S1T. Click here to see full specs[/qanda]Hi everyone! I have some questions about my ASUS 2014S1T. I use it mostly for burning Dual Layer DVD+R discs. I had problems with some discs (Universal DVD+R DL with RICOHJPN D01; and LG DVD+R DL with CMC MAG D01). Very bad media. Now I using Verbatim DVD+R DL MKM003 and I have better results, but not so satisfied. I burn them with Nero 9 and make tests with Nero DiscSpeed I burn them at 4x, because at my opinion results are better:

Burned @ 4x, Scaned at 8x

Burned @ 6x, Scaned at 8x

After that I was confused because I scan one disc at different speeds, and the results was very different:

Burned @ 4x, Scaned at 8x

Burned @ 4x, Scaned at 4x

My question is how to make disc quality test, in what speed? In which result I can trust? Why the record is better in slow speed?

Please delete this topic because it is repeated here