I'd buy it if I didn't already own one.
Is there a discount if his sister goes?
I only quoted your post because the "editer" told me I couldn't do a "bump".
Anyway, the thing that got me excited about the 1D IV was how accurate the color duplication is. Coming from a 7D2, the colors amazed me. I think my only true upgrade path is the 1D X ll. I shot next to a guy with a 1D X and while he likes the camera a lot, he said the differences weren't huge between it and his 1D IV.
The 5D IV might work as well..... but the faster shutter speeds would be a sacrifice for some of the stuff I do.