Upload & Sell: On
I went from the 1DsIII to 1DX. I don't miss the extra pixels, either.
P.S. I have 1DIV for the type of birds that fly, especially the small ones.
Jim, I think you may wish to try the opposite, contrary to this forum's wisdom. For small BIF, such as Robin, Common tern, Swallow, Pijun, etc.......you should use 1DX, not 1DMkIV.
Now, for bigger BIF, such as Eagle, Crane or Goose, where AF performance is not that critical, you could shoot with 1DIV as well, if you feel that some extra pixel density should help you.
Now, the reason is that in the case of smaller BIF, AF performance has probably 100 times more significance than some extra detail which you might, at least in theory, capture. That is why you wanna use the best focusing camera (and lens) in your arsenal on those, even if it doesn't have the highest sensor pixel density.
That's the way I see it, YMMV.