This is why it would be a real hard call for me to go 5D4 over a 1Dx1
I have used these cameras a lot
The AF systems on the 1Dx systems are phenominal. Gotta say that If I could get a refirb 1Dx1 cheap, or a low count 1Dx1 in the 2500.00 price range,,, I would be leaning 1Dx1
Reasons are AF system is great. Build and weather sealing. Im never over 12800 for wedding work. Since the update on the 1Dx1 12800 is very very good with a properly exposed file. Have not seen 12800 on the 5D4 to make the comparison.
The 1Dx1 is not going to have the forgiveness of the 5D4 or 1Dx2 files. You can miss by 1.5 stops either direction with no penalties. A 1Dx1 will really show in darks and shadows at 150% where as the 1Dx2 and probably the 5D4 will not....Theres your cushion on the newer sensors
I see everyones points. But for me its hard to beat what the 1Dx bodies offer over the 5 series
The only reason I dont have 2 1Dx2 bodies is because they are too heavy for my wife who has tiny hands and cant carry that much weight for 10 hrs at a wedding. She wants and needs a 5D series body