Just got the KS7090 (Germany's equivalent of the KS8000 US/KS7000 UK) 55" set and very happy with the quality after some calibration. Coming from a 7 year old Bravia KDL40W5500 so definitely a major upgrade.
I'm using the rings settings (
http://www.rtings.com/tv/reviews/samsung/ks8000/settings) but with color tone warm1 and backlight set to 5 for non-HDR content.
However, the settings menu and HDR options are a freaking mess as others have pointed out. Took me a while to figure out the quirks of the menu to finally get HDR working right but now it's pretty darn awesome.
I do have some questions though:
1) Using built-in apps such as Netflix and Youtube do not seem to give me the "A HDR movie is playing" notice in the top left corner. Is this a known issue or does HDR not trigger correctly for content which definitely supports it? (e.g. Youtube HDR videos)
2) Samsung website says the latest firmware is 1150.7 - however my set is on 114x (don't remember the exact version) and does not find a newer version online. Can I safely update via USB?
3) Game Mode and HDR - the hassle to get this working properly is just ridiculous with the amount of manual tinkering which has to be done every time. Any easy ways/solutions to work around this? Do we know if Samsung is aware and working on a fix?
4) I'm using custom calibrated settings for white balance and color tone (rtings), will this result in full or limited range colors? I don't want to use the auto setting because I'd rather prefer the color calibrated settings which look phenomenal to me.
5) Apparently my Sony STR-DN860 AVR does not properly pass through 4K HDR so both PS4 Pro and Xbox One S need to be connected to the TV directly. This is a major pain in the ass for sound as the TV connect box apparently does not route back 7.1 PCM via ARC (it may be a limitation of the ARC specs) so the best I can get is lossy 5.1 DD/DTS via optical. Any AVR users out there facing the same dilemma? This is for a 2015 set, any chances of a firmware fix? The STR-DN860 supports 4K and HDCP 2.2, but can not pass through HDR for some reason.
All in all, I think I really like the set and HDR improvements for games are clearly visible. I just think that with all the troubles (manual tinkering for picture settings, AVR audio limitations for HDR) I should have waited a year or so until these quirks are fixed.
As amazing as HDR is, I can't help but think TV manufacturers are rushing it with weird settings, menu choices and HDMI spec limitations. It will take another year or two until HDR settles in and becomes a truly hassle-free experience for everyone.