It is the first Nikon product that is a disappointment to me. Forget using with NEF files. Maybe I was expecting more than I should. But Nikon does not give file transfer times. Nikon support gave me 3 meg per second. It is not more than 1 meg per second, or one jpeg per second. You need to transfer only jpeg's and hope you can swap out cards with the NEF files. It is the only option I know of.