I have the Q8FN and updated today. Immediately noticed the brightness decrease as well. It's absurd. Not sure about Q9FN, but this update definitely screwed up Local Dimming with Game Mode on as well. It's absolutely atrocious now.
FIX THIS SAMSUNG!!!
Going to keep an eye on it over the next week or so. It's just when going through the menus you could see the brightness of the picture. It's just sdr is not as bright as it was on normal tv. Going to try messing with the settings a bit.
I have managed to increase from 55 to 75 the Caption Brightness in the service menu of the TV and now it Looks better, but still not as it was in 1270. Something else was modified, that's for sure. At least i have the brightness back, but this is not an experience i want to repeat. Sorry Samsung...
I had a bad image in HDR mode after update to 1290.4 - blurred, dark and bad colors. I've made factory reset in the service menu and picture quality now is good like was before the update on fw 1270.
I think that after the update to 1290.4 HDR mode did not work although it was turned on.
I have 55NU8000
This is definitely not an upgrade 1290.4 SuCKS, picture is really, really bad and colours are off,skin tone bad, less detail, fuzzy, very dark in dark scenes and less depth also. The previous update was much better, so what the hell?
SAMSUNG FIX THIS DISASTER!