I own and use both cameras...different uses for each, honestly so I couldn't tell you. Each camera has its own pros and cons. I will say for general everyday shooting, I prefer the 5D4... and note that the 5DSR is a significantly slower camera (FPS, shot-to-shot) in use than either the 5D4 or the 1DX. It is also not quite as good at high ISO...but in well-lit scenarios, if you put a good lens on it, it's unrivaled in IQ. I prefer the OOC colors of the 5DSR to the 5D4, the 5D4 has a flatter (more neutral) output but that's not necessarily bad. It does mean more work in post for images where I want more vibrant colors though. If you're blown away by the 5D4 IQ, the 5DSR is on another level altogether, except in the dimmest lighting. But again, you do have to own and attach a top-notch lens to it in order to truly realize its resolution. IOW, a 24-105 ain't gonna cut it...
Here's my general breakdown...if you do more of the following, what I would lean toward:
Still Portraits, Landscapes - 5DSR
Event Shooting, HDR, Travel & Sports - 5D4