I have a specific "D4 or D800" question -- I have and plan to keep a D800. I want a second body so for some shooting (especially sports) I can keep two lenses ready to go, or at least avoid changing in dirty areas. A D800E came immediately to mind, but ....
Is 10/11fps really a game changer in sports?
I do this for a hobby, and the other D4 advantages are just not that important to me. But on the D800 I shot single shot sports, because 4fps almost invariably misses the peak action.
For example, a volleyball spike - will a burst almost ensure a shot of the ball near the hands? Or is the motion still too fast? I've been staring at youtube slow motion trying to figure out how fast 10fps really is in relation to motion, but without much success.
How "fast" is 10fps really? Is it worth $3000? And no, I have no access to one to test, only the D300 and D800.