I did an enlightening test while checking out a new small OTA on a mount during the afternoon. I was looking at a light fixture with a 5" Mak on a completely inadequate Twilight Nano mount (I didn't buy this for the mount but was curious as to how bad it would be.) When making focus adjustment at 173x the damping time was 10.5 seconds after release--completely nuts! So I put the VSP's under the tripod and...3.5 seconds. I got the same results in both configurations several times. It was still long, but the mount became usable with the VSP's.
I then put the same OTA on the Twilight I mount as intended, in the recline position. The damping time was only 1.5 seconds. Adding the VSP's cut it to about 0.5 seconds--too rapid to adequately measure, but averaged around 1/3 of non VSP. I had my son try each configuration and he saw the same when refocusing for his eye. Not bad for a 23 yr old set of VSP's.