I don't mean to be refuting you say. I really would like to verify what you say is true and the scaling is good maybe with newer revisions. Its definitely 1440p as the display even says 2560x1440p. Ive seen this on three different 39 inch seiki's and one 50 inch (a fourth coming as my dad got a second one for home). So far its been pretty bad on everyone I tested. It was very obvious to my dad too as the blacks aren't any where near black. Here is a lossless 75-dpi terminal text which does not have anti-aliasing (when they are aliased it seems to come out better):
Can you tell me if all that text looks fine/is easily readable? Especially the bolded part like being able to see the circle in the center of the b and the a in 'dekabutsu' ? If you could take another close-up picture (it really doesn't need to be as close as you got it but like 1.5 inches away or something of a big grouping of text at smaller size (instead of a single letter) would be helpful. Even if you have to get even farther away whatever it takes to be in focus. I understand if you dont want to go through the trouble of this. I took the pictures of mine via an iphone 5 (so not a great camera) but they came out pretty decent.
Also if you look at this image:
And compare it with another computer or at 3840x2160 does it still look similar or does it look like the the last one I posted in this picture:
I would really like to find out if the scaling is actually ok on some models of the 39 inch (as I am sure others will as well). I would love to verify your results and I hope yours really does have much better scaling than the ones I have tested so far.
Also I take it if you enable GPU scaling and thus the dipslay says 3840x2160 but the OS is outputing 2560x1440 (so video card scaling) that it looks pretty similar if its enabled/disabled? I know on mine the video card scaling looks *WAY* better.
Giving you strait PNG's i think is more of an apples to apples comparosin (so your looking at the same things I am) rather than comparing other stuff.
Even better yet look at this screenshot:
These are anti-aliased fonts but compare to what the picture looked like for me (especially the text on the vew bar: