I got my seat new direct from Ultimate Seats over winter... It is a hard plastic.Did Ultimate use plastic for the seat's pan as another poster seemed to mention?
Far as I'm concerned it's either metal or fiberglass. It'd surprise me they'd use plastic for their seats' pans given how expensive the seat is. Seat pans take a lot of beating and last thing you'd want there is plastic.
I've had great experience with seats using fiberglass pans.
The factory seat is plastic too...