I installed a regular non-dampened sprocket on my (now sold) 2005 DL650 a few-four years ago. The new non-dampened sprocket definitely created less noise than the well worn OEM sprocket, but that's really not fair to compare worn vs new parts.
I would bet that the dampened sprockets do indeed make less noise or otherwise Suzuki would not pay the extra money for the dampened sprocket. And, it is likely that the noise created by the non-dampened sprocket is of the decibel ranges which aren't that noticeable to the human ear, but rather are noticeable to a sound meter during a drive-by sound test.
18 1000 XT yellow. Bunch of goodies installed.
2015 Yamaha WR250F- Street plated woods bike
Previous rides- about 25 different bikes, mostly dirtbikes.