I purchased a refurbed D7100 last year, and it hasn't been the greatest experience. Part of that is my fault, I admit. When you buy a refurbished piece of equipment, know that you get a warranty that is shorter than for new gear. Therefore, you need to really get the equipment out and test it IOT see if it has issues that weren't found or fixed in the refurbish process.
I've also got a couple of refurbed Nikon lenses, and one of them also operates at the edge of acceptable performance.
That said, there are many who are totally happy with their Nikon refurbed equipment who will continue to purchase this way, and I wish them continued pleasant experiences. As for me, I'm done purchasing Nikon refurbed equipment. (Oooooh, I can't believe that I said that.)
WM