When I print out the detailed settings of DSL v5 and compare them to NAL-NL2, I see the obvious reduction in compression ratio of the soft sounds from 3-4 down to 1.2. In the louder range CR seems to go down from 2-4 to about 1.7.
The first knee point for softer sounds seems to go up in DSL to about 47 at low frequencies compared to 40 for NL2. And for the second knee point DSL is at 62 compared to 55. However, I have no idea how significant or insignificant that is…
The other obvious difference is that the compression method (CM) used for DSL is Syllabic, while NL2 is Dual. My understanding is that Syllabic uses faster time constants, while Dual is slower. It does not seem definitive whether they are adaptive or fixed. I do see in the software that this can be overridden though. Not sure of the implications of doing that?