The PDI glass from Pinball Decals is the absolute very best.
I presently own and have tested all of the optical glass out there along with invited guests to my home. Starfire, museum glass, Invisaglass, PDI glass.... Its a run away winner with the PDI glass and I've been testing for years now.
Skeptical? - Open invitation to anyone to come see and play my collection and decide for themselves. Boulder, Colorado, locals and travelers always welcome. I have done this demonstration of the different glasses many times.
It baffles me when people pay $150 or $200 for a unique mod to a specific game but not a little more for the best pinball upgrade of them all. And its transferable to other machines so go ahead keep it if you sell a game.
Put some people together for a moderate or large order. Then ask Pinball Decals for a discount and split the shipping. This is what I've done and I still have a few sheets to sell if you're local.
Note: I am not affiliated with PDI or Pinball Decals and am only an enthusiastic customer. Besides, I love talking everything pinball and showing off my collection. Stop by and see for yourself the difference.
Shoot me private message if in Colorado or traveling here.