Apaflo wrote:
The D500 has 1.6 fstops more dynamic range at low ISO values. It is slightly better at ISO values around 2000, and at ISO values higher than 3200 the two cameras have about the same dynamic range.
Except for very high ISO work, where they are similar, the Nikon D500 has a very clear and distinct advantage.
You might also want to consider frame rates and buffer sizes for shooting bursts if you will ever shoot birds, other wildlife, or any kind of sports.
Thanks. Your pointers are echoed by others - driving home facts I should have paid better attention to.