I have 2 of these units. Tiny. The size of a small box of wooden box of matches and work great! Nothing else comes close. I've used 3 Garmins and I also have the di-GPS Mini. The a 4 inch cable to your 10 pin connector and your not fighting RS-232 and the long cables or the expense of the Nikon adapter.
I have one each on my camera strap of both my D3 and D300 permanently. This keeps the hotshoe free for the flash. I use the mini to swap around on my other camera.
D3, D300, D2X & D200 New 14-24 F2.8 too! If your not shooting Nikon your doing it WRONG!