Image Quality / Grey gradient / Greyscale
Image Quality
Samsung decided to equip this display with a semi glossy coating. Reflections are being reduced but not eliminated. If there are bright objects in the background you're able to see their shape.
Grey Gradient
Using the SE790C with standard settings - brightness 100, contrast 75, sharpness 60 - grey gradients are very good. There is no coloration visible and all steps can be told apart.
Greyscale
Also the greyscale is very good. Even the brightest steps are distinguishable. In order to see differences as best as possible it's recommendable to sit straight in front of the panel, since viewing angle stability quite quickly has an effect on discoloration.