The image quality from the Crystal is amazing, when it's all correct. You get the headset and immediately you're blown away with the picture. After a few days of owning it things start to annoy you. The fit is terrible, it just clamps you with 2 points on the front and back, no side support at all so it wobbles all over the place when you turn your head.
The image has slight doubling the further away from the centre you look. Stars and orbit lines in Elite Dangerous look like those red/green 3d glasses with chromatic aberration, but it doesn't double in other things.
The audio is out of sync and the new firmware fix gets rid of the bass completely and makes the £150 DMAS headphones sound worse than £5 throw away junk headphones on those cheap walkman things.
The headset doesn't work like a regular DisplayPort headset. It needs to connect and log you in to the PC, like what a Quest or Pico does. This is finicky. You run the Pimax software and hold the power button on the headset. Sometimes it works, other times the headset turns off again. Sometimes I spent 5 minutes just trying to get the thing to show the PC image in the headset.
My eye tracking stopped working towards the end of my Amazon return window. My options were to deal with Pimax support, which I wouldn't wish on anyone, or return it for a refund. I took the refund.