I was able to purchase a D500 late in 2017. Prior to that my main camera was the very capable D7200. The D500 garnered praise for it's autofocus, frame rate and deep buffer. I have now used the D500 for several weeks and want to share my impressions.
I have mostly used two lenses with the D500 up to this point. One for indoor high school basketball (Nikon 80-200 f/2.8) and the other for wildlife shooting which consisted of mostly birds (Nikon 300 f/4 AFS). Both lenses had seen considerable time mounted on my D7200.
Having shot the D500 for several weeks and several thousand frames I feel that I am still in the process of finding out just how capable the autofocus on this camera is. For me it blows away the D7200 autofocus. In addition to the autofocus, I also love how the camera renders images and it's ease of use (customization).
The most significant difference for me has been the new autofocus system. The D500 autofocus acquires focus lock almost immediately while the D7200 would often hunt or pause prior to locking in. This was especially true of birds in flight. The D500's autofocus is so good that if I miss a shot it's because I didn't place the autofocus point where I wanted it. When it's locked on to a moving target I'd say it nails the focus ~90% of the time.
Example #1: My brother and I were walking and saw a red shouldered hawk in a tree. Two teens walked by and the hawk didn't budge. As soon as we got a good angle on the bird I stopped and it immediately took to the air. I was fast but not fast enough, as I ended up with this image. The focus point was behind the hawk, but the error was all mine. Since the bird took off I basically got my lens to my eye and hit the shutter. I believe that if I had the focus point on the head then it would be in focus.
1/2000 f/9 ISO 800
Example #2: Saw this Fosters Tern repeatedly cycling thought an area working a small pod of baitfish. All I had to do was acquire focus and press the shutter, the response was instantaneous. I never would have gotten this shot with my D7200.
1/2500 f/8 ISO 400
Example #3: Once again this shot would be very difficult to get with the D7200. This Osprey was taking off and I had a split second to get it, and the camera nailed it. In the past with the D7200 the pause to acquire the focus means that I would have missed this shot as the bird was quickly moving away from me.
1/3200 f/8 ISO 800
When shooting birds with the D7200 I tried really hard to stay at or below an ISO of 800. I try to do the same with the D500 but have pushed the ISO for several shots.
Saw this male Great Horned Owl roosting and while I was there it purged a pellet, which I captured. I shot handheld and am pleased at the amount of detail and color at ISO 1600.
1/320 F/5.6 ISO1600
The first shot that let me know that the D500 was going to provide outstanding images. This Hooded Merganser was shot from behind a blind using a tripod. The bird was close when I got this shot.
1/200 f/5.6 ISO 2000
Customization: One of the amazing things about the D500 is how one can set up the autofocus system in a way that it's very flexible. For example on the back of the camera is a toggle switch for changing autofocus points. This works very well and I have mine set up for group focus. My back focus button is set for single point AF. This provides me with the option to switch back and forth from one to the other as needed. I set up my shutter button as the release but that's my preference. I'm still working learning the capabilities of the 3-D AF mode.
While the D7200 is an amazing camera it doesn't have the autofocus to hang with the D500, especially in terms of speed of acquisition and then staying locked on. I believe that the D500 renders better images at higher ISO levels than the D7200 in terms of noise. I try to stay at or below 800 for both camera's, but when I've had to venture above that level with the D500 I have been very pleased with the results. I have yet to even put any pressure on the absurd 200 shot buffer but then again I never felt constrained by the D7200's buffer of 16 raw files. If you shoot sports or wildlife the autofocus of this camera will allow you the possibility of getting images that weren't available with cameras with lesser autofocus systems. My final thoughts have to do with the fact that I now don't need to carry a monopod or tripod to get great images, I needed to do that with the D7200. I feel that the D500 handheld allows me to get better pictures than the D7200 on a tripod! The question of if that makes it worth the extra $1000 is one that you'll have to figure out for yourself.