Here's been my experience in the past year- had a GB premium built Sept 2016, playfield dimpled deep and quickly, got an Aerosmith Premium about 2.5 months ago, there are dimples, but nowhere near as bad, deep or as many as my GB, bought a Dialed In 3 months ago, has dimples, but are taking a lot longer to show up, not very noticeable and not as many as GB or AS. From my experience it seems as Stern may have starting using more dense wood lately, but I might have just gotten lucky on AS and got one of the better ones, not sure, but those are my first hand observations on those 3 machines in the past year.

I kind of assumed the same thing on Stern using several manufacturers. My AS looks worlds better than my GB did, but you still notice the dimples more than Dialed In. Dialed In definitely has dimples, they all will dimple to some degree, but the dimples aren't as noticeable, you kind of have to look for them where as they are easier to notice on AS and on GB you could see them from across the room!