I just got a NIB GZ PRO. I documented the playfield protector install and posted day 1 gameplay. The rules and strategy are very similar. Same number of shots. 11. The Pro plays faster.
2 main differences on the playfield. 1. The MechaG shot is much much easier on the Prem. 2. The Pro building shot is tighter than the Prem. That is really it.
If you can do without the spinning Mechagodzilla and the falling building then you will be very happy with pro. Especially if you like hard fast pins.
Either pin is better great. Top 3 easily. Better than MM, AFM or any 2 flipper pin.