The Ducky Secret M is still the best shape I've ever used. Unfortunately, I can't use it because the lift off distance is like 11 meters and the "custom" setting for surface calibration does not work. In fact, it never worked, and they never fixed it which gives me low confidence in them.
Hopefully this one will be good out of the box because you can rest assured that they will never put out a firmware update once it's in the wild.
Can you tell I'm a little bitter about the Secret/Secret M?