I saw one of the 2" two blade models Sunday....very light, cut for a 6 pitch but usable with a Bolly, and the supplied backplate, knurled on both surfaces (a good thing) had a bit of standoff from the drive.......
As an aside, those that have created aeroplanes with Dave Brown or Randy spinners can use the Randy backplate (either carbon or aluminum) or the Windy carbon unit.
Good quality...
Another shortcoming is that they come with only 1/4" adaptors.
Good quality and a nice shape.