I hear great things about the D850 tho I have never used Nikon—only Canon and now Sony. I have never tried a crop sensor Sony either, but they are small and light. Am really liking the full frame A7rIV tho high iso not be its strength—especially at pixel level—but am very happy for my landscape work—mainly on tripod.
I had used crop sensors in the past, in the early days just about all of the sensors were crop sensors as you know. When I did switch to my first full frame camera the Nikon D700 I was sold on full frame, and never ventured back to a crop sensor. That is until this Sony A6400. I know it's not totally the IQ I get out of my full frame D850. But I didn't get it to replace the D850, I got because it had pretty good IQ, and it was so light and portable. When I found I could get totally acceptable Milky Way shots with it (as long as it was early in the night and the sky wasn't at it's darkest), I was really sold on it as a capable camera, and one that makes a very viable lightweight backup system when I travel, or when I am backpacking and every ounce of weight counts.
The menu system and the controls on the camera itself are it's weakest points as seems to be common with Sony bodies. But I guess we learn to adapt. I just have no clue how an otherwise excellent camera can have a menu system so screwed up and illogical. It's almost like they wanted to be different from Canon and Nikon, and in doing so created an almost crippling menu system. In my research before I got the A6400, I could see that there had been improvements to the menu system from the earlier models until these current models, but they still are rather lacking.
With that said, obviously I find value in the Sony A6400, and have gotten some really nice photos from it. Almost all of my Winged Wednesday entries are from the Sony A6400 as I visit local ponds almost weekly to get fresh Wings for my entries.
