I’ll try to be super brief so as not to move too far away from the purpose of this particular thread. There is a lot more discussion on this in the isolation thread.
Love the dampers. I didn’t expect much, but they actually focus the sound quite a bit; put another way, it improves the precision or “outline” of the audio image. For me, they made the biggest difference on the rectifier and input tubes, and less so on power tubes (but still a bit). However, if you’re looking for a “tubiness” and/or a bit of a resonant, reverb-y sound (which is totally fine) then the dampers might take away from what you’re looking for.