I began with a red dot on my AR, but after a while I wanted to be able to reach out and touch someone and be able to identify targets at a distance. I ended up with a Strike Eagle which can identify close in targets quickly, yet provide long range accuracy too.
I keep my scope set at 1 (no magnification) when the rifle is in my bedroom closet for home defense. The only negative compared to my red dot is the extra weight. I'm glad I made the change.