I just compared my Pixel XL vs. my Motorola Moto X Pure out under the 12PM Texas sunlight.
- Turned off adaptive brightness for both.
- Set both to max brightness on the slider.
- Opened up the same webpage (yahoo.com).
- Also looked at my phone contact pictures.
The Moto X Pure was slightly brighter and easier to see/read with direct view.
When looking at an angle, the Pixel XL was easier to read.
Once root is available, I'll install the Brightness Widget and install ElementalX kernel to see how the Pixel XL looks with the brightness pumped up.
If it gives me 10% more brightness then I think it'll probably be just as bright as the Moto X Pure with direct viewing.
The Moto X Pure has ~715 nits according to some reviews and is just as bright as my old Note 4 was.