So maybe a 2080Ti will allow closure of the gap between the 5k+ and 8k with acceptable frame rates. At that point I believe you’ll be rendering in native 4k anyways so the 8kx would be a better choice if you know if existed to compare to lol.
Like many have said, going for either HMD and not directly comparing each, side by side, pixel peeping the whole time should make anyone happy.
If my survey was sent today I would choose the 5k+ based on everything I’ve read, heard and seen. Then an 8kx down the road. I have a while to decide so in the mean time I’ll spend hours everyday day looking through these forums and watching MRTV’s and Sweviver’s channels .