Its been around for a long time, i just happen to try it out and have been using it ever since for 4years? it does not erode that badly and visually looks quite porous also. Alot of freshwater users also use i think. But since marine pure came out, that was the hype ah.
Oh yea auto fleece the only issue is cost and also need to fit in the sump when its already pre designed so abit of a bummer. Unless making new sump to incorporate. So far i've been using the old wool mechanical method, works like a charm still hahaha.