We all hope, if i get time ill go out looking at an old X500 more one of these days, had 3 of those now, one of them is truly a unique sample that for my setup challenges the RS600, and even one of the lesser samples overall outperformed both my N7 / RS2000 samples, I would love to have an N series sample as good as my best X500, so I'm still looking.
No doubt that the N series has some unique qualities, the biggest obstacles are the bright corners, dust blobs, and color uniformity.
I for sure have seen and calibrated an X7900 with bright corners, and fair to say that unit was impossible to calibrate for other reasons.
today i swapped a lens on an X5900 that was impossible to get good focus uniformity on, had a spare part X30, that lens was much better, so a successful transplant.