I am making the (for me) huge leap up from a D80. I shoot mostly wildlife, often birds, with zoom telephotos, and landscape (often sunsets over water) and set my D80 to use the larger (think it is 8mm) center focus & AF to AF-C. I almost never use the focus points (unless using the flash on auto (green).
So, I wonder if using the 39 focus points will actually capture birds in flight. I also set my AEL-AFL button to focus and use the shutter 1/2 press to exposure, then often reframe to the original object focused upon and shoot. I think I will continue with this practice, but am listening.
I have never "gotten" why folks want the multi focus points.