Polite thought regarding this well repeated reference to 8K-X is barely superior to 8K.....
How do Pimax actually know there is little to no difference between 8K and 8K-K is they haven't tested it yet though?
And we know they didn't test it when they made that statement as the technology didn't and still doesn't exist to test it at 90hz as no GPU exists to run 2x4K panels at a 90hz - the industry standard minimum for VR.
A cynic could think that Pimax are telling backers a 'half truth' probably to stop existing 8K backers demanding they want to drop their 8K pledge for an 8K-X ONLY) as Pimax know its far less profitable to invest in and market a $1000 'niche market' HMD so then logically the fewer 8K-X for them sold now during the KS especially, the better. Hence they limited numbers to 400 and people were like, huh?!
I would liken it to Ford offering a Focus RS car at the end of the product life cycle to the enthusiast vehicle market so when the car is newly launched they can concentrate on the vanilla model years beforehand. As selling in volume nets maximum profits.
Personally I think once the hardware exists in 2019, (at the very least to watch 180/360 movies if PC games are too high a hardware requirement at 90hz), then 8K-X will still be the best ultra wide FOV HMD experience available. Thus, I believe 8K-X gen 2.0 with either wireless or single cable will become the new 8K model in 2020 or so and the 8K-X backers now, in 2018, will effectively and perhaps unwittingly have become beta testers for Pimax as they know we'll give endless feedback and feel 'grateful' only 400 of these headsets exist in the world in 2018.
If so that's a pretty smart business model to reduce costs. The enthusiast 8K-X backers using the gen 1.0 headset will be uber excited and tolerate various quirks (2 bulky cables etc) and other phenomena because they want and demand the best, for a premium price.
Thus to me, the idea the 8K-X is impercievably different to 8K comes with the unrevealed but critical caveat 'when we tested 8K-X using a 1080Ti GPU and NOT at 90hz.