PAGD is discussed all over the place and the inventors are still alive and well.
As I recall the output is pulsed and of high energy, and something about the electrodes wearing out quickly.
In my personal opinion, which is biased, the PAGD is not practical. However, gain is gain and some is better than none. Discharge tube devices that exhibit excess energy use the divergent current method same as Aspden's concentric capacitor device, but one uses a displacement current and the other conduction current. Either will spin the stuff, but which is easier to switch? Comes down to personal preference.
The other method is to use hv pulses to produce the density change.
Some may notice that pulsed output and AC output devices do not have a static mag field. DC output devices do have a static mag field. This is indicative that the aether motion, scalar wave, etc. interacts with a magnetic field in a constructive way. My guess is that virtual charges separate just like real ones do, and separated virtual charges become real charges.