[Driven97]

Unless it's an actual race car where it's only goal is the time on the clock, rubber is the best, IMO.

I've had worn out rubber, poly, delrin, and now back to fresh rubber on my (70% autocross) car. Wasted a lot of money and effort.

Poly binds and/or squeaks.
Delrin transmits notable vibration. And eventually squeaks.
Rubber just works. I didn't experience a notable loss of precision going back to rubber, either. While it's conceivable something would show up on the lap timer, it's not worth it for me.

Or, to put it another way, there's a real good chance you're unhappy if you go with something other than rubber. There's a 0% chance you are unhappy with fresh rubber.