Re: Seymour duncan pots?
The regular easy-turning model is a new Bourns pot, that is also available with the Bourns brand on them. The YJM's are an even easier-turning Bourns pot that I think only Duncan offers. They are pretty much the same as the EVH pots, but you can get them with a knurled shaft, the EVH only comes with a straight shaft. Can't answer about the tolerance thing, I'm planning on buying a couple and measuring them to see how close they are.
Al