So much misinformation here. The term scaling is being thrown around, but it's such a broad term that it's actually confusing and missing the point. Scaling can literally be the decices ability to scale an image to another resolution, higher or lower. The Xbox one s scaled to my 4K TV and the output is native, the image being used is not. This is not what the PS4 pro is doing. The IQ of the image has no improvement in this case.
The fact is, 4k requires aporximately 4 times the rendering power of the PS4. Sony wanted to keep cost down, so they doubled the rendering power instead, added ram and some other extra tricks.
From my understanding...
Checkerboard is 2 frames of data being used to produce a 4K image by means of a checkerboard, i.e. Alternate pixels take from the first and second frame. Each frame requires the power of 2 ps4s, hence why the pro is speced as such. Usually this sounds like a bad idea.... However the PS4 pro has special hardware to track geometary at 4K and I put that data somehow into the rendering process to make an image similar in quality to 4k. It is my understanding that looking at the images if you are not moving, produces an almost native 4 image. When the game moves, quality is still excellent but is compromised slightly.