I recently bought a WASD V2 87 "barebones" with mx browns. I put Imsto dye-sub PBT keycaps on it. I bottom out on every keystroke, which produces a "clack" sound, which I actually like. Nevertheless, I wanted to see how the board sounded and felt with O-rings, so I tried a few keys with black 50A-R, blue 40A-R, and red 40A-L O-rings. I didn't like the deadened sound or the somewhat mushy feel; therefore, I removed the O-rings.
BTW, the WASD keyboard has Costar-type wire stabilizers. I have also tried Kul and other boards that use Cherry stabilizers. Although Cherry stabilizers make it somewhat easier to change keycaps on the stabilized keys, to me the Cherry stabilized keys feel mushy. The Costar-type stabilizers on the WASD board provide a crisp and even response no matter where the key is struck; moreover, they do not rattle. Even the spacebar is rattle-free, which was a pleasant surprise. I should mention that I did lube the stabilizers with "MechLube2" from Elitekeyboards.com.
Although the spacebar does not rattle, it makes more bottoming-out noise than the other keys on my WASD board, and so I am considering using O-rings only on the spacebar, but based on my experience thus far, I anticipate that I will revert to having no O-rings at all on the board.