I have a castellano fango, the aluminum version of the silk, and it’s definitely an interesting feel for my uses of riding on gravel and railroad ballast
I can see why it didn’t see a huge amount of success, the short travel rear suspension concept in general, at least during its time of relevancy. It’s good at one thing and not great at a lot else. It’s outright uncomfortable on really harsh terrain, because the rear starts to flex out of sync with the obstructions on the ground.
But on fairly consistent gravel, where the bumps turn more into vibration? It’s amazing, you could sit and sprint as fast as you want and would barely feel the ground, while not losing too much power pedaling like you would on proper full suspension.