>Can some knowledgable Nikonian put his (or her) into >explaining why FX is so hot?
It's not FX, it's the D700. I can't explain it either, but from looking over the forums here, the D700 is clearly the most loved camera by a wide margin. (I don't have one. Maybe if I did, I'd have an explanation.)
I'm pretty sure the D3s is a better camera than the D700 based on the specs, but not on owner approval. Look at the D3 forum and you'll find D3 owners with various issues and complaints. The same is true of every other camera and every other forum... except the D700. Everyone who has one loves it, and claims it is the most amazing camera ever. No D700 owner has ever said anything bad about the camera. Visit that forum and see for yourself!