I don't know. I can't imagine that it's like night and day, but from a construction standpoint it does allow duplicating it. So let's assume that you build one using 28 layers of glass, but it's too stiff, you can build the next one using 23 (or whatever) layers of glass and each subsequent build would be the same. With wood, you can thin it out, moving from 1/8 to 3/32, but there is no guarantee that the next batch of wood has the same reflex characteristics. Plus, in my experience, when you get that thin 1/32 of an inch is a little tough for the mills to do accurately.
Interesting, I guess, is the watch word.