Turntable

As John Curl says......."Condemnation without Examination is Prejudice"

Depends on your theory.

Just to come clean, I use aerospace air bearings, both thrust and radial.

Low friction bearings allow for smaller motors, less noise/vibration, simpler controllers, better dynamics, quieter playback, greater simplicity etc. Air bearings are great and achieve these goals if you don't mind dealing with a pump.