Yeah, the fps difference between this and my D3s I was using at the time is pretty significant (9 vs 4.5), but in the field it really wasn't as bad as I expected (well, in regards to wildlife), it did take some getting used to, and being able to anticipate the action a little more, but all in all not too bad. I would LOVE the 800's to do more fps, but in the end if I had to choose between the 12mp at 9fps of the d3s, or 36mp at 4.5 fps of the d800 again, all else being equal, I'd still go with the D800 (for wildlife), the added MP comes in SO handy, and the ISO difference between them, while noticeable, isn't that bad especially for such a massive jump in resolution.
this was actually my backup body and what I used at automotive shows, I'm still keeping the d800e for wildlife/nature/etc. but I've got a few financial issues coming up this year that I need to prepare for, so I'm planning on selling this, selling my 600f4, and probably the 300f2.8 (my 2 favorite lenses

), then getting a different body to use for the journalism events that I cover for my business, then getting a 500f4 as my only supertele for wildlife, and saving the difference since the 500f4 is a good compromise between the speed and length of the 600f4, and the portability and hand holding use of the 300f2.8