The 5D IV photos do seem to come out well, judging by what's been posted here. I know people say.. it's the photographer, not the camera, but from my own experience, it's a combination. As Tom mentioned, the files from the 1D IV are nice. I think its strengths have made me a better photographer. I only use the 10 fps when I shooting birds in flight. It does come in handy there.
I say this a lot, probably because I'm a color blind man. The 1D IV gets the colors right. Other people can play around with color adjustments. I make horrible mistakes when I try that unsupervised. I was post processing a kitchen for my wife a few years ago and when she looked at my final take, she cringed and said: do you know you made all the recessed lights red? I had no idea. Anyway, the 1D IV files catch what I saw at the time I took the photograph. That ends up being huge for me. As long as I do my part, the camera performs flawlessly. It's not an indoor camera, at least, not for me. But most of what I do is outdoors and it really shines there.
I'll bet the 5D IV is similar in that regard, with more flexibility indoors. I might end up with one some day. I'd rather had a 1D X2, but that isn't likely at the moment.
My affliction is blues, greens and grays. Can't tell the difference. I calibrated my monitors in hopes of them catching what I cannot see. So far either it works, or people are just too kind to say differently.