It is my belief that with the advent of the 1640 & SolidBurn.
Added to which media appeared to be less consistant (quality wise) too.
BenQ f/w for the SB capable drives were/are less precise.
So earlier drives with basic settings may well be at least as good. If not better.
However if you accept the capabilities of SB then in the long run.
With ‘Learned Media’ the 1640/1650/1655, should equal the best. If not surpass it.
Using SB can have a downisde, in that a rogue disc. New batch etc.
Can throw the learning process off.
This should, if acquiring media from the same source (in theory) be minimal.
Sticking on the topic of SB, if you use it.
The only gain (again in theory for the better media like TY Verbatim) is that SB would be enhanced.
So learn quicker & better.
Although because of the Lite-On influence. the 1650/1655 f/w has not been developed in a way that gives any hope of this happening.
So stick with what you’ve got is my opinion.