My opinion so far on the C6K.
The remote is a POS, it weighs about 5gr and feels pretty flimsy, the battery cover falls off pretty easily, very annoying.
Plex seems to freeze up after about 2mins while I was watching some Southpark, this is not a big issue, I usually run it through my Xbox anyway, but this could possibly be fixed by changing some settings on the server.
Edit: Come to think of it it must be some compression issue as I did watch some 4K movies on plex over wi-fi no issue.
4K Content on Youtube looks amazing, I got lost in Youtube for a few hours just watching random things in 4K.
Dstv Sports looked really good, I don't normally watch MotoGP but I couldn't stop watching, the colors were amazing, now I really want 4K sports content
Kids movies look really good, the colors really pop.
The sound is decent for a TV, much better than I expected.
So far the only bad thing is the POS remote, I might just replace it with an air mouse remote if possible.
If there is time I will test some PC gaming this weekend. I just need to find a decent HDMI cable about 5 meters long.