Al,
The MD is an incredible machine, and not only the variable hz, but the soft/hard tissue settings make life easy. The tips are NOT interchangeable, the MD has plastic “hubs”, and the air/water mix is IN the handpiece vs. at the tip in the WL. Therefore the different hubs due to the fact the water/air mix.
You ought to go to Kimmel’s and see it, it’s neat! Happy New Year to you Al!
All my best,
Mark