Will a BenQ 1650 report C2 errors when performing a quality scan with Nero CD-DVD Speed?
Yes it will.
Will a BenQ 1650 report C2 errors correctly when performing a quality scan with Nero CD-DVD Speed?
Maybe, maybe not. Try reading this thread for a recent discussion.
When we talk about C2 errors, there are actually three different kinds and different drives report this in different ways.
The three types are E12, E22 and E32. These correspond to one, two or three+ bytes corrected during the C2 stage of error detection/correction. For Audio CDs an E32 error means that the sample couldn't be read correctly and the drive will have to interpolate (i.e. guess) a reasonable value. For data CDs there's an extra layer of error correction, so E32 errors can often but not always be corrected.
There are at least these different ways scanning drives report C2 errors:
C2 = 0 (drive is incapable of reporting C2)
C2 = E22 (this is what Plextor drives report)
C2 = E22 + E32
C2 = E32 (Plextor drives report this as CU instead)
C2 = E12 + E22
C2 = E12 + E22 + E32
The bold one is probably the most correct, but not necessarily the most usual way of reporting C2. Some think the bold italic one is the correct way however.
I'm guessing but not 100% sure, that NEC DVD burners from the ND-3500 forwards either report E22 or E22+E32 as C2 errors.
I suspect but don't know for sure, that BenQ DW16xx drives report only E32 as C2 errors.
Regarding your ScanDisc scans I would suggest you use the Read test instead of C1/C2, because then you check for actual reading problems.
Your NEC drive may or may not be scanning reliably, and it may depend on the scanning speed. Your NEC scan has some strange spikes, so try scanning at some other speeds (I personally use 8x for my NEC 4551) to see if the spikes go away.