I really like this!
It’s just a great composition with lots of interest in the clouds as well as the texture, detail and colors in the canyon walls. Good overall depth, too.
As for the sunlight on the upper portion of the canyon walls, I think that part looks good! What strikes me is that the canyon and the water appear to be too bright, it doesn’t seem to blend as well as it should, there should be more of a defining line between the shaded rock and the rock in direct sunlight but this is just my opinion.
I done a quick edit using a mask in ACR (selected with the select object brush), then lowered the exposure and contrast quite a bit.
I also selected and lowered the exposure and contrast a little in the sky.
It’s still plenty bright enough to see the details in the canyon in my view.
This is just the way I see it. Hope you don’t mind the edit.
Edit: I just wanted to add that I hope to experience this place in person sometime soon.
I’ll be adding this to my Grand Canyon trip itinerary. Thanks!