Purchased the 75"
I went to a local Big Screen store to check out TV's. They had a section with every level of 75" Samsung TV's(they only sell Samsung) right next to each other. It was 7 in total. They were all running the exact same show at the exact same time on Comcast HD cable which is what I have at my home. I sat and watched a lot of different programming, NFL, Property Brothers, Fox News, Life Below Zero etc for approx 2 hours. All TV's were set to dynamic mode so I could do a really good apple to apple comparison.
Before going in I knew my price range limited me to the Q6 or the 8000. After watching everything side by side I could obviously see a difference between the 8000 and the 2 lower priced models but I could not see any obvious difference from the 8000 all the way up to the Q9.
I also watched a soccer match in 4k on all the TV's at once. The Q8 and Q9 did look slightly better with the 4k match going but I really had to focus to notice the slight differences.
They also had the 82" 8000 close by and for whatever reason is didn't look as crisp as the 75" 8000 with the standard HD cable. They did not play the 4k material at the same time on the 82" with the 75" to really compare.
I really wanted to walk out of there with the QLED badge on the TV but I just could not see a any difference in the TV's to quantify any difference in the price. If I knew nothing about TVs and the Q9 was only $100 more I still don't think I saw enough difference that would have made me make that purchase just by watching regular crappy HD cable.
I have moved on from a couple year old 65" Vizio P series and the 8000 looks much better then that set did. There is no clouding or dirty effect, I especially noticed it when a tv show is panning or on a light one color scene. I don't care what rtings says about viewing angles, the 8000 is 10 times better then the P series in that aspect. Where I sit at the dinner table is a horrible angle to watch TV and the P series looked pretty bad. The 8000 does a much better job looking at it from a bad angle. --Still not as good as my old VT50 but is more then adequate.
I did look at the viewing angles in the store with all of the TVs and did notice the Q8/Q9 were slightly better from a bad angle but not as far apart as the 8000 was to the P series.
I have had it about a week and am still working on the settings. I tend to like dynamic mode the best but some scenes are def. oversaturated.
I purchased a XB 1 S the same day so I would have a 4k player and purchased the original Predator movie in 4k. I did notice the movie was a bit grainy in close up but don't have any other 4k dvd's to compare it with so it may just be that its an old converted movie. The streaming 4k shows however do look great.
Watching Amazon movies in 4k and in regular HD looks amazing and the few games I've tried also look great.
I have not heard any crackling or popping on the set. I do see very minimal clouding right along the left and right edges but I really have to look for them and almost have to walk up to the TV to notice them on a all white screen.
The one draw back this TV has is glare. I think my old vizio had more of a matte screen so the glare wasn't as bad but if you are in a room where glare can be a problem, I don't think this would be a good choice for a TV.
My main concern has always been trying to read reviews and make TV purchasing decisions. Even just going into costco and looking at 4k demos didnt help much with pulling the trigger. Finally getting to really sit down and watch these TV's side by side helped me make a decision with no regrets.