I don't think that overlay is what S37VEN thinks it is. What he just said makes no sense at all.

EDIT: He posted while I was typing.

No, they give it a nice shiny finish. They do not repair color, damage, or anything else. If your playfield has flaws this isn't going to fix them.

Is anyone else a little bit concerned about the potential for condensation buildup under such a large sheet of plastic? That playfield is constantly heating up and cooling. Whenever you have a solid plastic membrane and heat transfer you get condensation. In this case there would be zero way for the moisture to escape and it may work its way into the ink/wood. Let that sit a while and now your playfield protector is impossible to remove without taking chunks of ink.

Is this a concern?

Yeah, I think it will vary heavily by environment. An F-14 might be a safer than average game, too, because some of the arrow inserts will be raised enough to potentially allow airflow under the protector.

Everything affects ball travel. Even on a single playfield ball travel changes depending on the cleanliness of the playfield. I've never heard anyone say we should let the games stay dirty so as to avoid the effects of wax on the playfield...

Heh, well at least I don't see anyone saying their protector has bubbles like mylar.

Over time any tiny crevice in any pin is going to accumulate some buildup. Wax, dust, dirt, etc. The only way to avoid that would be as you said to lift the protector. That's not something people are likely to do all that often given that you have to strip so much of the playfield to do it.

The thing that interests me most is seeing how the balls mark these things up, how they get polished out, and if airballs start cracking corners off of them.