This helps me a lot.I got my 65" X900F on Saturday. I also have an LG B7A OLED and I've become concerned about my TV usage having the potential for permanent burn-in. I play lots of video games, some with static HUDs /other sorts of fixed images, so I started looking for something that I could game on and not have to worry about damaging. I tried the Q9FN before this TV, which I was initially impressed by, but by the end of the first weekend I knew there was no way I was keeping that TV. I made some posts over in that forum as well. I'll touch on them a bit here but if you want the full story head over there. That was my first review on this site and I got a few compliments on my reviewing style, so I thought I would do the same here for the X900F.
Image Quality: Picture looks nice and crisp. Older, non-4K content upscales nicely too. Sony's always been pretty good at that though. I would dare say it's a bit sharper than my OLED, but not by a whole lot. I've just noticed a couple of subtle things that look a little bit clearer on this TV than the OLED, but only because I've seen those images a bunch of times at this point.
Colors: Not quite as wide of a color gamut as my OLED or the Q9FN. It's a little less saturated than the other two but not in a way I would say makes it look worse. You could try and use the "Live Color" setting for more saturation. I personally don't like to use additional image processing though so I leave it off. The uniformity of the color distribution is MUCH better than the Q9, there were so many imperfections with the one I had. There was no displaying a solid color on my Q9, you'd see varying lighter or darker patches all over the place. Not the case on the X900F and I am thankful for that. I'll take a slightly lower color space over numerous imperfections any day of the week. This is more of a uniformity thing though, so lets move on to that.
Uniformity: Like I said in colors, this TV is much better at displaying a solid color than the Q9 was. As Rtings noted, the corners are slightly darker than the rest of the screen. It really isn't that obvious, on a full white screen you might notice it but on anything else you'd be hard pressed to see it. I've noticed a lot of Sony's seem to have slightly darker corners though. Blacks are nice and deep with no clouding issues. Also no obvious banding and there doesn't appear to be any dirty screen effect. Every TV brand seems to have some quirk with uniformity to what I've seen, any imperfections here are localized to just the corners and the Q9 was basically everywhere. My OLED has some areas where it suffers too. My OLED has a vertical band along the left side that has a slightly yellowish tint to it and others have commented theirs has it too, be it there or somewhere else on the screen. Fairly noticeable when displaying whites, brighter colors also show up as a slightly different shade in that area. I can deal with the quirks of this TV easier, it's big enough to where I'm not looking at the corners that much anyway.
Brightness (SDR): Good brightness for SDR. I keep mine at 25, 50 is the max. It's plenty bright at 25 even in a fairly well lit room. Not much I can say about SDR brightness really, most TV's these days are capable of hitting a pretty good brightness for SDR content.
Brightness (HDR): It's not as bright as the Q9, the only thing I will miss about that TV. The X900F does get decently bright though, bright enough for me anyway. Best of all, no super dim and washed out looking picture when in HDR game mode! On the OLED, I hate the HDR game mode picture. LG, for whatever reason, decided this looked better for that mode. My guess is lower brightness reduces risk of burn-in and that is their logic to it being "better". Interestingly enough, the Q9 was also dimmer in HDR game mode by default. With both of those TVs there were some settings you could change to bring the brightness back up, but it still wasn't quite as bright as the other picture modes. This is not the case with the X900F, HDR game mode is as bright as you would expect it to be without having to mess with anything. I'm much, much happier with the HDR game mode on this TV. I just leave it there all the time where I would have to switch modes when watching movies on the others for a better HDR experience. I've only watched the two John Wick movies on this TV so far but they looked really good. I didn't notice any blooming into the black bars. I wasn't totally focused on them so it might have happened a couple times but I didn't notice it. Which brings us to the local dimming.
Local Dimming: Works surprising well considering it has much less zones than the Q9FN. I believe the 65" X900F has about 60 zones while the Q9 has about 480. Sony is working some pretty impressive wizardry with their dimming algorithm. Honestly, I can barely tell the difference sitting right in front. Off angle, yeah it's easier to see the difference the extra zones made, but it's not a night and day difference either.
Motion: This is another area where every brand seems to have their quirks based on feedback I've seen from others. I'm not that sensitive to motion but I know some people are. Going from the OLED to the Q9 I could see a little difference in motion handling but I can't really describe what exactly it was that made it different. This looks closer to the motion on my OLED for whatever that's worth. I haven't tried the new X motion clarity because I don't like to use motion processing either.
View Angle: Obviously not anywhere near as wide as my OLED. It's about average for a VA panel. I've seen worse.
Image Retention/Burn-in: Not going to happen since it isn't an OLED or plasma.
Input Lag: Feels about the same as my OLED when in game mode so it's pretty responsive. I think Rtings said the B7 had 21ms in game mode and this has 25ms, so its pretty comparable.
For some minor things: I'm not a huge fan of the new "feet" supports. I had to set them inwards to fit it on my TV stand. I think they look a little weird compared to the supports on last years Sony's, but they do hold the TV up nice and sturdy. Some people might be a bit let down that only HDMI 2 and 3 are capable of receiving HDR signals. I run into a receiver first, then into the TV so this isn't a problem for me. The Android apps are a bit slow and clunky at times but I use my Roku for all of those so this doesn't affect me either.
Overall though I think this is a pretty nice TV. For my money it's a better value than the Q9FN, and even if I'd gotten a panel with better screen uniformity I would have the same opinion. If I could just get the brightness from the Q9 and the OLED viewing angles combined into this TV that would pretty much be perfection. We're probably a few years out of anything that will fit that description though, but this will definitely do while I'm waiting for that day to arrive. I'll pop back in a bit over the next few days if anyone has any questions on things I didn't cover. This ended up being a pretty lengthy post, thank you for taking the time out of your day to read it.