I finally had time to finish reading this thread completely through. There definitely seems to be some variation in panels and maybe (just maybe) some made in certain factory or silver ones are better. For example in our case the one that is perfect has serial DN and silver while bad on is FK and space grey. It turned out that I cannot really get mine replaced with brand new one. So I would have to take a risk by return mine and hope dealer would not notice it has been used at all, because only way they allow returns is that you have just opened the box and maybe turned it briefly on without actually using it. So in the end it could be that they just refund it partly or don't even accept the return, so I don't know if it is even worth to try knowing how my luck usually is, if it is even remotely possible that things can go wrong they will (I'm a living and breathing example of Murphy's law).
I've been comparing our two units several times in past few days and screens do act pretty similar way when you tilt them in various angles but for some reason the one that does the more obvious two tone shift (white-red-blue instead of white-almost undetectable pink-green) is more noticeable but on the other hand it seems to have somewhat better contrast, especially when tilted. Worst one just makes even slight 1 degree change from straight on position colour shift more obvious that the other, even it also does shift colour even slightly tilted but due to different kind of colour shift it is just not as noticeable. Anyway more I use my bad one, less I seem notice it but I do see it every time I want unless I hold it in certain position. Reading this forum with my phone is one of the easiest way to see the problem when I compared between upper and bottom part of the picture. Also I've been using mine mostly around 30% brightness or even little less in dim environment and doing comparison with that screen brightness. So am I just expecting too much with dim settings since pretty much everyone it this thread is talking about issues with 100% screen brightness? I think from what I have briefly tried our phones at 100% that issues became maybe less evident in that case. Also I've been running my comparisons with True Tone on or even Night Shift on because I like both modes and I do prefer warm screens and preferably accurate D65 calibrated over cool ones.
Mine also has obvious popping sound from the chassis but I did remove it from the Apple case and examined all screen and back cover seams I did not notice that those parts had lifted from corners or similar signs of adhesive problems. There was one small parts where I thought it looks like slight gap between rubber seal and steel frame but it was not in the corner and I could not even fit a corner of a paper there, so I think it is nothing to worry about Also pressing corners did not make popping sounds. There are popping sounds when pressing back cover around Apple logo or by twisting the phone gently in my hands. Also I was able to confirm that chassis of the phone is straight so that when I place it on the table face down it was completely even against the table. So I don't know if that is more than just a cosmetic flaw, probably not since I called my local place that is certified service and asked that, they said probably no need to worry about it.
There is still one thing that bothers me and it is the battery. In both phones battery menu says battery capacity is 100% but I've been checking their condition with iMazing and the one with better screen has stronger battery. Mine has been hovering around 2760mAh and even peaked once or twice 2776 but obviously after every charge cycle it has been very slightly going down and it now currently 2745. Better screen one has very strong battery and has peaked over 2800mAh many times and is even worst situations around 2780 and my wife has been abusing it a lot because she often lets it run below 20% even I have told it is not good to let it go so low. Mine I have been trying to use as carefully as possible and I have been charging it around 34-45% in worst case and I'm pretty sure if I'd let it drain more I would get battery capacity dropping under 100% since running it low is when actual "recalculating" battery capacity usually occurs. Also I should mention that both were straight out of the box 2784 and 2782 (before charging them, other values I mention here are taken after that), so pretty even and the better one has actually improved from that and other one weakened but it was disturbing that mine came out of the box with only 1/3 charge while that other was over 3/4 so if they charge these at the same level during manufacturing process why that other did lost some much charge during shelf life?? Also I have noticed few times that mine something skip percentages when it is going down during use, like yesterday it went straight from 83% to 80% during I was using it (I was intentionally keeping track of the battery use while I was using it). It does seem that I need to charge my phone pretty much daily or after two days if I don't much use it but my wife goes often three days on single charge but she uses the phone a little less that I. Also I compared battery percentage between the two by using them side by side with same screen brightness doing the same things and while other one dropped 10% during that test mine dropped 13%. But just last night I tested again but this time I used one phone at the time for certain amount of time with same settings and doing the same thing (browsing this forum) and this time they were so that mine actually used less battery during certain time. So I don't know what gives. Maybe difference came from actual use in first test and I actually used that another one less even the screen was always on.
Anyway what I'm trying to ask about the battery is that what is your capacity reading in iMazing or Coconut Battery and have you got readings from different times like what it was when it was brand new and how it changed or did not change after first few charges? Currently mine is 2745mAh and 9 cycles (reported by iMazing) and other one is 2780mAh and 7 cycles.
