Got my Perfect Pixel UHD430 in.
This thing is incredible. I previously used a Dell U3011 for about 6+ years now and was waiting for the right time to upgrade. Since I use my monitor as my TV as well I wanted something a little bigger, but not too big (and 43" is about the biggest you could go for regular computer use imho).
No dead pixels, solid metallic front with no gaps or weird things that I saw mentioned with the UHD420 (although the back is plastic and the only thing really cheap feeling), 4:4:4, HDMI 2.0 and all that stuff, 10bit color in Win10, 60hz at 4k (using it with displayport and a 980ti). I tried changing the refresh rate to 100hz at various resolutions but none worked.
The OSD came switched to English out of the box so that was nice. I do see a Freesync option in the OSD but I have Nvidia so I cannot test anything with that.
You definitely have to calibrate it when you first get it. My color profile out of the box leaned slightly blue and I sort of fixed it but I think I really have to get a physical calibrator to get it right. It seems dumb that I have to buy a $120 thing to calibrate my monitor just one time?
Upscaling looks good from both DVDs and Blurays (where the 4k BluRays at?!)
There are some Korean user reviews that provide alot of pictures if you are curious:
In any case I had no issues, plugged it in and it worked perfect. I'm extremely happy with my purchase..