I will come at this in a different way. I bought my D850 on the second of November and was pleased as plum when I got it... only to discover about 3 days later that it would not follow birds in flight... I set it up just as my D500 and it still was not right, I played with it for 5000 shots... and I took it back to get my money back... it was a no go. They told me that they found nothing wrong with it, to which I said bull crap. So I got got it on my tripod, and I shot moving cars (grills) yes a hard subject, but then so are birds, and after about 100 shots with it I called Nikon. They asked for three images, and I did not hand pick them, rather I sent 3 consecutive images. upon taking a look at the first image the Nikon Person said... Send it in, there is something wrong with your camera. I sent it in on Wednesday, had it back the next Wednesday. I went out and shot moving cars with it ten minutes after I got it back. Lo and behold, they were sharp and less noise than I had seen in any image in the past.

Sure there was a problem. The D850 was a piece of crap... until it went back in. true, QC should have caught it, but they did not. A dear friend of mine is to get her D850 back from Nikon tomorrow for very similar issues. I expect it to be fixed as well. But out of the thousands of D850's out there... only a couple have had issues... and they are correctable... that does not sound like there is too much noise. I think that you need to read and look at the images that are out there and really judge for yourself rather than letting someone else tell you what you need or dont need. and if you cant afford it... by all means... dont buy it. get something else or use what you have... just dont be a nay sayer because someone else's best friend's third cousin thought that it was not good.