B&H has $100 instant savings on reburbished D600s until March 2, 2013. That brings the price to $1599.95!
BUT! The warranty is a "90-Day B&H Refurbished Warranty", not Nikon USA. B&H refurbs are sold through their used department, and they state "The B&H Used Dept does not distinguish between grey market and US-warranted merchandise for any item we sell." Nikon USA won't service grey market items, even for a fee.
Cameta sells "Refurbished USA" kits with lots of freebies for $1699.95, but the warranty is a "1 year Cameta Camera Warranty". Again, not a Nikon USA warranty.
Adorama states that the refurb D600 comes with a "90 Day Nikon USA Warranty".
I'm leaning toward Adorama because of the Nikon USA warranty. To me, that says that the camera is really a USA camera, not grey market, and Nikon USA won't refuse to service it even after the warranty expires.