TN's main advantage and generally only now is it's pixel response. It reduces pixel transition motion blur but it really only matters in fast pace FPS. High Hz no longer really an advantage due to AHVA / Sharp IGZO (IPS-type) and MVA panels now have a high Hz panel.
TN panels aren't naturally easier on the eyes. There are several things that affect that.
High blue light is reportedly one issue with it. This is why BenQ and Viewsonic start including low blue light mode. Makes things more red of course but it does it's job.
http://www.tftcentral.co.uk/reviews/benq_xl2720z.htm all the way down at low blue light mode to get an idea of how it works.
The other is pulse width modulation (PWM). PWM is highly dependent on the individual and the amplitude, and cycle speed / Hz rate. The flicker free monitors essentially is lack there of of PWM and then there are hybrid PWM which is what Eizo and Samsung tend to implement. PWM at low brightness is great for color stability on LED platforms due to how they work with not getting enough power.
Doesn't matter what panel it is. This is all manufacturer implementation.
TN panel being washed out is mostly due to viewing angle limitations. The color shifts is what causes it. That said, any panel can be washed out or if you use HDMI on NVidia graphics card without fixing it.
As reported by PCper it's set to $600.
I actually plan to get the MG279Q and do a sort of mini review of it with the tools I have, an i1 DisplayPro and random cameras.
I won't be able to do more in-depth things. PWM I can sort of get with a camera recording but I won't be able to confirm high Hz or whatever.
I will not be able to get response time and signal processing lag and I don't plan to get the expensive gear.
That said I'd get this if you're really stuck at $400:
http://pcpartpicker.com/part/benq-monitor-gw2765ht