Good:
36MP Full Frame CMOS Sensor.
Sturdy weather resistant construction.
Excellent ergonomics.
Extremely efficient high ISO behavior.
Superb battery life.
Bad:
Slow burst shooting.
Wi-Fi available only through an add-on than circumvents the weather resistant sealing of the camera.
A bit heavy to carry around outdoors for extended periods of time.
Bottom line:
The Nikon D810 is highest quality Nikon out there. The continuos mode shooting could be faster to accommodate fast shoots as sports. The price is low compared to it’s Canon equivalent the 1DX.