Very much my personal impressions, as there are plenty of in depth technical reviews from people with far more VR experience than me. Comparing it to the 5k+ and Lenovo Explorer. I’m skipping audio as I haven’t tried the MAS speakers yet, I have unfortunately developed a degree of hearing loss in my right ear a couple of years ago, so I prefer PC speakers without positional audio in order to hear everything clearly with my left ear.
- Packaging
Excellent premium quality overall, but it seems to be a little random with what is included. For example, some have mentioned they received a cleaning cloth and so on, but I did not. I received the unit, MAS, and a welcome note. That’s it.
Edit: the small pack with card instructions and cleaning cloth was there, but as suggested by @neal_white_iii, I had to partly rip out the glued liner to get at it
- Display and optics
I have only tried native resolution so far, and love the lack of SDE. It really started to bother me on many apps with the 5k+. It may be only be a slight improvement, but colours seem better. I did notice some obvious ‘grey mist’ in what should be dark areas on HL:A etc obscuring some detail, but some tweaking of brightness and contrast made it acceptable, if not perfect.
On to the big problem for me. I’ve made a few posts about it already. So far I cannot get both eyes to be in the sweet spots. It seems impossible for me. When looking head on, I get a slight blur in at least one eye, or sometimes both, which removes the crispness. I can always get one eye crystal clear by turning my head and looking at content from an angle. Keeping my head straight and glancing to the left or right will leave one eye clear and one eye quite blurred, which is uncomfortable.
I have always needed to set mechanical IPD to minimum on Pimax headsets, but no offset or eye relief combination works to date. I have tried to just hold it my hand and find the perfect position, but have not been able to do so. To get one eye clear means blurring the other one slightly. I am using -0.5 offset for best depth at the moment.
The 5k+ had some initial problems with this but I did achieve it in the end - however perhaps right on the limit. I cannot do the same here with the 8KX, I think something has changed. On the old unit I used -1.5.
However, despite the disappointment of the slight blur, it is still a fantastic looking image and the best I’ve ever had in VR without doubt.
- Comfort
I cannot remotely use the thin foam supplied, it is completely unusable for me. I am currently using a thicker leather VR Must foam, but even this is slightly thinner than the velcro and foam combination I needed on the 5k+. So far, adding velcro has not helped with the IPD and clarity but it may be that I need to double the thickness.
The MAS is a big leap up in comfort and stability from the cloth strap + dangling counterweight I had on the 5k+, which was just maddening at times and limited my VR time. I like having the dial, much like my Lenovo headstrap and I can get fairly comfortable much faster. I don’t have any issue playing for one hour plus, which was often difficult on the 5K+.
I am also lucky, I have hinges that have the full range of movement. They did offer some resistance at first, but no problems after just a few swings.
However, it’s not perfect. Due to the front heaviness of the headset, it often ends up pressing on my cheeks (not too bad on the nose), and needs readjustment. Tightening the dial helps, but can lead to slightly too much pressure on the forehead. I’m looking forward to having a proper counterweight solution attached, which is on the way.
- Performance
Due to the apps I’m using, this is generally a tough one even with an i9900k and 2080 Ti. I’m not in any rush for a new gfx card as I like to skip at least one generation (think I did quite well going from SLI 460GTXs -> 980Ti before the current card!). I have only tried native mode so far, and largely relying on FFR and Motion Smoothing where possible to get reasonable detail levels whilst having an acceptable frame rate of 37/38 without significant drops. I am using PT 1.0 at present.
ED was my one main app for years and the reason I got into VR, but I have finally largely stopped playing. This is a lack of gameplay and content issue, rather than a VR thing. It is extremely demanding due to PP. Average FPS is in the 30s. Might try Small FOV to compensate. I used to run the 5k+ on Normal FOV with 45/90 for planets / space with PT 2.0, SVR 0.25, HMD 1.25.
DCS. Very casual player but also hugely demanding, especially when close to the ground or in busy areas. I have not tweaked it much as I don’t play too often, but using the VR quality preset it can just about maintain 37/38 at a reasonable altitude.
NMS. My new favourite, but also very demanding. I have been tweaking this, and last night tried Small FOV, which gives a solid 37/38 whilst allowing me to increase GPU intensive details to Enhanced. More may be possible. It would be great to avoid PP, but currently some sprites require it. A mod might be able to do this.
HL:A. Runs amazingly well, especially with @NextGenVR’s command line tweaks to eliminate the need for PP. But of course it is a linear game in a limited world, so the demand will never be as high as on open world games.
Aircar - just a bit of fun, but wow, because you can turn everything up to max and have full quality. Perfect demo to show someone who is not a gamer or into VR.
Blade and Sorcery - I went straight to the older U7 for the Star Wars mod. Runs pretty good, given it’s not that well optimised yet. Equally it’s arena-based, and a lot of textures etc are not such high quality. Huge fun for a quick bit of visceral combat!
There are others still to try, such as Seeking Dawn, VTOL VR, Boneworks, Assetto Corsa, and Skyrim, to name a few.
Look forward to that, and despite one major con for me, the pros outweigh it and I’m enjoying it much more than the 5k+. Hopefully there is still a solution for the IPD issue out there, will have to see 
PS Also looking forward to using the Pimax Experience, but on first test last night the performance was terrible for some reason, all the profiles were stuck at the same incorrect values, and I could not edit most of the settings. Will return to that later.
Not Happy?’…guess they’re already anticipating that one