It's alotta hoopla..
While I'm sure it works good enough, there is not actually a 'better' turner than those offered by Sinclair. And you can use any of the case lathes out there. If you can't turn brass right with a Sinclair, then give up on turning..
I think my current case lathe is a neilson, and I hold an NT4000 in my hand for 'perfect concentricity'.
But just to break down the hoopla, you can visualize the 21stC angles produced by supported points to cutting point.
The casehead is supported so all the wobble is seen at the cutting point. The turner is back supported, so all the wobble is again at the cutting point. Now draw a line in your mind between both supports, and from either of the support points to any wobble at the cutting point. See the angles? See that the case neck is not straight w/resp to the mandrel?
The only way to keep it straight is to completely suspend(in your hand), either the turner, or the case. There is no better way.
But this'll fool folks I'm sure...
Always amazing how shooters are motivated to buy reinvented light bulbs, yet they never bought into to the original light bulbs. It's as though 'new' is assumed better.