I was trying to understand why would you want to use an adapter with an SD card on D700 vs a CF card. Let me know if I got it right. Are you a professional who takes thousands of photos at a time and you need to have a large number of cards with you to switch around. And you don't know how many CF and SD cards to bring with you, so you want to standardize to just SD cards?
I've just found the same thing with an adapter. My reason for wanting this is my GF has the D700, and guess who has to find more CF cards when we're traveling? My cards for my D600 don't fit her camera. Unlike many of our incompatibilities, this gadget only cost about $12. My history of trying these types of think runs into the hundreds of dollars.