I usually don't request body advice like this but I am really torn, having gone back and forth on this.
I currently have a 6D and a 7D2, and use the 7D2 with the 100-400 II for birding and general wildlifey stuff. The 6D takes care of the other stuff - landscape, family, etc.
I recently purchased a 500 II, and have been considering getting a 3rd body so that I can carry two birding-capable bodies with me in the field. I was amost convinced that I should get the 5DsR to put on the 500 II, so that I can leave my 7D2 on the 100-400 II. But now, i am wondering if I should just get a 2nd 7D2 instead. I know all the pros and cons and have gone round and round on this. The noise and DR differences between the two in the 800-1600 ISO regime where I usually reside when birding are not that compelling to me. I know that with the 5DsR, I get this amazing croppability as well as the ability to use it as a high res FF body for other applications like landscape. But I can save almost 2 grand with a 7D2 and wait for the 5DsR Mk II iwth the onchip ADC to (hopefully) come out.
Help me make this decision! 



