Nikon could do well not to launch, with lots of advertising drive, a camera that wasn't properly field tested. I feel the Df project was subject to wrong decisions by the overzealous bean-counters. There is nothing wrong, not at all, with the underlying concept, my reservations are for the implementation of it.
I feel that the advertizing drive was targeting mostly Hipsters and life style users who are ready to pay a high price for a mediocre product like SMEG Refrigerators, which they treat like a RAW egg later. Usage pattern: snap shots & showing off.
What then happened was that a lot of people with honest and earnest photographic ambition and professional usage patterns needing a field robust camera took up the piece.
This is not a FM-2 or OM-1 or Leica M3 that you can take up the Everest, through the desert sand storms and to the North Pole and it will work flawlessly with outer wear only.
This is basicly an overpriced D600 style camera with a second layer of GUI on top of it, an exceptional lens compatability and a very good HiISO sensor, the best Nikon had available at the time.