Slaw, I don’t know the viscosity of Townshend’s silicone. I do know that some Rock users have experimented with thinner versions, but I’ve used only the stuff that came with my table, the old Elite version. My table’s spindle was very close in diameter to the shaft, needing to sit overnight to fully seat.
Arm’s that employ damping at the rear, near the bearings, use it more for damping the bearing assembly than for the whole arm and cartridge. Applying damping at the cartridge end provides much more damping of arm/cartridge resonances. One (American) reviewer thought the Rock to have a too "controlled" sound due to, presumably, the damping trough. The table can be used without the trough, but I got mine specifically because I’m a Decca/London cartridge fan, and they, having no internal damping themselves, benefit greatly from the Rock’s damping. The Decca was used in the development of the Rock design, and their pairing is a match made in heaven.
But ALL arms suffer from resonances, and the Rock damping greatly reduces the peak in output all arm/cartridge have at their resonant frequency. The Rock design is known for having very clean, tight bass, and the suppression of the arm/cartridge resonance plays a role in that. If you have subwoofers, or loudspeakers than go down to 20Hz, you are really going to hear the Rock’s great bass! And clean, "tidy" (as the British say) highs.
