I think what is happening is people are preferring the SR Suntour SP12 NCX Suspension Seat Post over the Thudbuster as it is less expensive and rumored to perform better. The Bodyfloat looks like a much better unit than either, the Suntour is probably a lot heavier but is way less money and there is no wait time to get it.
The above is just speculation. What I know for sure is that my Suntour has been on my bike for a week and I love it and can highly recommend it. Because it eliminated the problem 100% and doesn't have any flaw beyond weight, which I don't care about, I don't see how spending 3x the money for something better would make sense for me. But your situation may be different.
Great question... I've only tried the Thudbuster but really like these kinds of products. Less complex and expensive than a rear shock and works great if you already have a suspension fork
I updated your original post to link to the Thudbuster and Body Float threads. I'm sure you've seen those articles already but it might help others find it. Specialized has also been experimenting with a vibration dampening seat post that is more of a flexing part vs. full moving arm but I'm not sure it ever came out? Was called the Cobl Gobl R (cobble gobbler... yum.)
Hey @DashRiprock, That happened before when Brian(J) was looking to order. When I emailed them they told me they were out of stock and would be in stock on a specified date. Sure enough, they were back in stock on that date. You could email them to find out when they will be back in stock.
Thanks, Charly. My Marathon Plus tires/tubes were a similar deal. I agree with Brian's points above/your thoughts previously on the SunTour and am headed in that direction (simply too much money for the BodyFloat).