Dave: It may be why you are happy but you must not conclude that if you ever use a rip fence that is mounted on a floating table you will no longer be so happy.
You can accurately rip with the fence mounted on a floating table. I do it frequently, in fact did so today. The secret is simply to install the floating table rails with care]
Dusty I can see why your method eliminates the problems I experienced but that requires you to mount the table the same way every time. To me that didn't work I kept forgetting to lift here and push down there.
The 520 is the solution and I believe the reason Shopsmith made the 520 fence rails the way they did. They know the problem and silently fixed it with the 520.
And yes I'm sorry for in my part in the hyjacking of this thread.