I have the space shuttle overlay, haven't installed it yet. People today are putting such thick automotive clear on their restored playfields these days I don't know that people truly care about balls rolling around on wood, because they aren't.. They're rolling on polyurethane. Once the paint is ruined on a wood playfield, you're either attempting to touch it up yourself, completely stripping both sides of the playfield to have it professionally touched up, or you're still stripping everything off but swapping out the playfield from CPR.

Wood will continue to be used probably forever more for playfields (at least as the main base), but I like the idea of art on a sheet that can easily be replaced. It's like people that ask "why are we still using asphalt for roads, why aren't we making roads out of solar panels?". Because asphalt is really cheap, it's pretty durable, and even when it wears down you still get a good grip.

I don't think there would be any weight savings to layering plastic, you'd have the same density (plywood has air because it's engineered glued particles). Also how would you merge plastic layers? If you use an epoxy that's a lot of labor (expensive), you might as well make a sheet of carbon fiber. If you tried merging them with heat (like ultrasonic) you could potentially melt it where you don't want to and compromise the outside surfaces, maybe even warp the whole thing.