I've enjoyed my 1Zpresso K-Max, although in retrospect getting the blind shaker design in the magnetic catch cup of the K-Plus would have been nice. The external adjustment with detents was a selling point for me, despite it having a slightly coarser adjustment than comparably-priced manual grinders.
For what it's worth, I have a J-Max and hate the magnetic catch cup. It used to come off while grinding probably 10% of the time. I now leave a strip of electrical tape on it to keep it on while grinding.