After reading several reviews about the newer line of monitors, especially with 4K capability and despite their impressive picture and colors, when it comes to the basic parameters of gray scale, gamma and relative color accuracy, right out of the box, in many respects these newer technological phenoms are not much better than their previous CRT brethren. Hence, to get the most out of the set, a good calibration would still be in order.
I found the same thing with my new LG mid-range LCD LED 4K monitor whereby, with the ability to do my own calibrations, I was able to determine that while the relative gamma standard of around 2.2 in the 0-30 and 80-100 IRE range was OK, anything in between was around 1.6, after awhile, making the set virtually un-watchable. My LG allows a twenty point grayscale and gamma calibration and once I completed that to a 2.2 level up and down the scale, after tweaking the color a bit, the difference in the quality and watchability of the picture was quite remarkable, well worth the time and effort to tune things up properly.