Finally got some typing tests up!
This is well-worn daily-driver RealForce 87U of many years inside a Norbaforce housing. The finish shown is the textured powder coat Enigma Black.
Four configurations demonstrated:
1) No risers installed, Silverstone foam liner (not included) installed against lower plate
2) Risers installed, Silverstone foam liner (not included) installed against lower plate
3) No risers installed, no foam
4) Risers installed, no foam
The keyboard is resting on a marble surface.
I can barely tell the difference between them in person (or in the video), but my personal favorite sounding option by a slim margin would be flat + foam.
Sorry for the slightly echoic room. I plan on installing sound dampening material--just haven't gotten around to it yet.