jasonpatrick wrote:
I think the 1dIV is the best compromise given what you told us which is, "2nd camera in unlikely 1dx fail, little extra reach for 500mm f/4 and birds".
On the other hand you also mentioned that you were leaning toward keeping the 7d. If that's because you need the cash generated to purchase the 1dx, I think you already made your mind up. You obviously like the 7d or it wouldn't have a spot in your kit.
To me, the choice is either keep the 7d cause it's the most cost effective way to move to a 1dx, or keep the 1dIV because you're looking for a complimentary camera to the 1dx that can give you most of what you have on the new camera plus a 1.3 crop for "reach".
I already have the 7D as I had moved towards a "lighter" kit with the 5D III. I also have the 1D IV and use it primarily for wildlife. Recently though I tried a 1Dx and fell in love with the high iso capabilities and picture quality. I see myself using the 1Dx for 99% of the time. The "backup" would be in the unlikely event of the 1Dx failing or for the odd occasion where extra reach was required. Luckily I am not needing to sell any body to findance the 1Dx.