Just in case anyone is considering these, and they are unsure of their capabilities, I found that using the
Celestron VSPs, dampening time was reduced from around 6 secs to less that 1 sec on my Vixen 4" refractor mounted on a GPDX on a 1.2 metre portable pier.
The amplitude of the deflection appeared not to be lessened, but the dampening time reduced dramatically. In other words – they work very well!
Cheers
Dennis