We used HDPE strips for the bottom of our shooter. as noted above, we noticed more improvement from changes to the backing over changes to the deck.
Our backing material is of choice is vertically ridged rubber conveyor belting material.
You can see the 7 HDPE curved sections, and the green rubber backing inside the shooter.
The 7 segments are all cut from one 3/8 thick piece of HDPE we got from a local plastics supplier. The segments nest inside each other. It was reasonably cheap. we could adjust the height using polycarb spacers, moving the slides up/down to suit.
Also, we turtle waxed the other surfaces the frisbee was in contact with. the hopper, intake polycarb and the feeder slot slide were all liberally waxed up after every few matches or so. Ask code orange how much of a difference it makes. We introduced them to it at IRI.