used many over the years and have quite a few personally.
ivoclar stratos is by far the nicest i have and have used, but the magnetic plates are stupidly over priced, like £20-$25 a plate
to the point where i hardly use it now.
if anyone knows of copy/compatable magnetic plates for the stratos that are sensibly priced id love to know.
magnetic plates are a must when doing lots of diagnostic waxing and large mouth cases.
Kavo is nice also,
but the one that gets the most use for me is the denars as there kinda the standard i guess.
also has a converter for the kois platform/facial analyser and that is one awesome gizmo for communicating horizontal plane accuractly.
the one huge downside of the denars is they do not maintain cross mounting accuracy. Have seven at our production lab and paid alot of money years back to get them all callibrated.
Within a few weeks they were going out of whack with each other again.