I like the softer light you got compared to the time of year I visited that place (early April) - much nicer tones to the colors for this part of the place. The pinks and reds add a nice mood to the scene. I saw more yellows and oranges with more harsh lighting dynamics.
If I may, I'd suggest a minuscule crop at the top to shave off that little bright part at top center. There looks like a green lens flare at the top as well. Here is an easy fix. In photoshop, make a new layer and change its blending mode to color. Then, using your brush tool at around 25% opacity color sample a color nearby and start painting over the green part. It will take on the colour you've sampled.
Excellent capture, it definitely gives me a sensation of spaciousness. Did you capture this while on a tour of Antelope Canyon? I'm planning a trip out there and was wondering if they would be worth going on vs. obtaining the permits and doing a self-guided tour.
. I have cropped and fixed the lens flare 
