Thought I would weigh in again. IMO - I think if you can afford it, the back up camera is one of the most important things to add to this vehicle. I measured today and it is 50"+ from the bottom of the rear window to the ground. The back up sensor works, but it is nice to be able to see what is behind you. Especially if you ever run out in a hurry. The sensor can't tell the difference between a kid and a trash can. The wide angle is a plus when in parking lots.
When we were first looking, one salesman tried to talk me out of the Nav because, well he didn't have an Enclave with Nav in stock. He kept telling me how expensive it was and to go get a Garmin. I finally said that I could really care less about the nav, it was the camera that I was adamant about. Of course, I had just read 2 articles about parents backing over kids, so I really felt that since mine were still so young, that it was a necessity not an option. It does take some getting used to. It does feel weird to back up while not constantly looking out of the rear window; old habits are hard to break. Imo it is a great investment.