I have chosen to send my 4K back.
Impressively sharp image until you move your head.
So close yet so far, Pimax got so close with the 4K, no SDE and a nice sharp image. Great for movies or virtual desktop but games, No chance.
I didn't have any of the other issues posted, IPD adjustment worked, Steam integration was seamless, no gyro drift (using most recent Piplay) but ghosting was so bad. Most noticeable in game menu's but noticeable enough in game to be very distracting.
Fingers crossed for Pimax that the 8k doesn't suffer the 4k ghosting problems.