Good cup. A pile of fines at the bottom. Bunn commercial grinder.
Might be worth $60 for someone with an expensive grinder. There's no way I'd recommend this to the average consumer, even if they had a passable burr grinder.
5 micron polyester felt. No fines (regardless of technique/grind), same cup quality.
Impossible to clean and too expensive to throw away every time.
edit: Oh -- I assume everyone's using surfactant to clean this thing carefully every time?