I have a '68 p/p and a '97 Zum. Sure the Zum plays a little easier and is easier to work on, but I think the p/p system is elegant in it's simplicity. No changer is more straightforward than the push-pull. One just needs to take the time to understand the mechanism and do a little planning when making changes.I now play LeGrandes and have never looked back. Why? If I go on a job or a session, I am confident I am going to have less tuning issues, the guitar is going to be more stable, pedals and knee levers more solid feeling and I can just play better on a guitar that plays better.
That said, I enjoy the slightly stiffer action of the Emmons. I can rest my foot on the pedals, without inadvertently engaging them.
As far as tuning stability, nothing surpasses the p/p. Once you tune the changer and set your pedal/knee lever stops, it's locked in. I seldom need to adjust the raise or lower screws. Usually I strobe in the open strings and it's "good to go". Like all metal neck guitars, it's a little temperature sensitive.
I play the Zum, a Pro II often, but tone-wise,"best of show" belongs to the Emmons.

