Ebony vs. Cashmere
The Ebony was a concern for me too when we originally made the purchase - mainly just because I thought it might be too dark overall. The cashmere interior is very nice, and I wanted a change since we'd always had flavors of "grey" inside. Unfortunately, my wife was really set on the ebony interior she'd seen on another vehicle.
I guess I'm easy to please, and I really do like the ebony interior. I also live where it's pretty hot in the summer, and I have not noticed any issues with excessive heat. I have all windows (except the windshield) tinted with UV-filtering window film, which really cuts down on the heat in the first place. Our truck is kept in the garage at home where the sun can't get to it. Also, the Denali's auto climate control feature (part of the remote starter package) works great, and we have no issues with burning our tushies or anything when we get in, even after it's been parked outside in 100+ degree heat and sun. It also helps to keep the moonroof "shield" closed when you're parked outside...
I wouldn't worry too much, and I think it's really a matter of personal preference. Post some pics of the new ride after you get it!!