Slow write and poor quality

I just replaced my GSA 4163B for a Benq 1640 because I keep reading good things about the Benq 1640.

I just replaced the firmware, nw on BSMB. SB-on/on, OS-on, WOPC-on

Here’s the media that I have:

MCC003
Writes at 12x in LG - 97 quality
8x in 1640 - not so good…

NANYA CLX
4x on LG - score: 95
8x on benq (but actuallty writes at 4x) - score: 78