I received and installed my Sam B low check rest and thumb rest; I'm liking them.
I changed the AT stock for an AX and the cheek rest, adjusted to the lowest limit, was right at the edge of usable. The check rest was an easy install and it lowered the height by 5/16ths over factory.
The thumb rest was a bit more difficult ONLY because when I changed the stock and re-expoxied the stem, it glued in the cup that held the stock retention nipple. Instead of being able to replace the cup with the Anarchy model, I simply resued the existing cup and screw. Not as professional looking as the replacement, but it works the same.