Well, did a masterclass this morning and tried the sound anchor out. (wooden)
The most difficult thing about it was getting in the right hole.
It is so small compared to the bottom of my bass, but I found if you have a really sharp endpin it will stick in the wood. Don't know how long it will last, but it worked really well as a rock stop on a tile floor. Didn't even have the tie secured...
However, I couldn't hear and discernable difference. My bass is so massive, it is hard to hear subtle differences in that kind of environment. Can't really say that it did or didn't affect the sound. More experiments to come on that front.
Brian