Microphonic tube resonances are a real problem and deserve to be dealt with thoroughly. Isolation platforms are very effective, but tube dampers should be used as well; the more damping the better. I am astonished that apparently a number of people feel as though the colorations introduced by tube resonances are beneficial to the sound; I am emphatically in the other camp. Resonance is one of the worst possible additions to the sound if you are looking for accurate musical reproduction, but this thread is actually causing me to wonder whether the "tube sound" that so many people love is partly or mostly due to tube resonance. Certainly there are other differences between tube and SS, but it is fascinating that several people feel that removing tube microphonics removes the "life" from the music. I should add that I like ARC gear better than most other tube gear because it just sounds more accurate and less "tube colored" to me. Maybe it's because the tubes are damped. I would be interested in hearing comments from owners of some of the good-sounding low-power SE triode amps about whether they have ever tested their amps for microphonics using the tap test. I've never owned one but it would be interesting to find out...
