Anybody still using soft rubber isolation devices?

Soft feet have plenty to offer. I use Brightstar Isonodes under my transport to connect it to my old-school, sand-filled Brightstar Big Rock platform. Makes for a very clean, clear and organic sound.

Would it be bad to place Navcom Silencers under the feet of a ScoutMaster wich is on a Salemander rack?

I use Isonodes to isolate my VPI Aries Scout motor from the stand.

I have 23 McCormack "Mod Squad" feet in my system, mostly under equipment or one support platform. I have another 12 or so Iso-bearings (soft ball design in Delrin cup) that support my Aesthetix Io.

No hard feet under anything except turntable stand, tape recorder stand and built in speaker spikes of the Dali Megaline.

If you look at the upgrade Grand Prix amp stands, their best footer is carbon fiber discs sitting on the floor, connected to ball socket design foot.

Yes, but not for my stereo. :)