I had a red dot on my AR in Arizona. It was OK. Longest shot with it was on a fox from one ridge to the next, approx 100 yards. The dot covered his body (top to bottom), and it did the job. But I decided that I prefered my 1.5-5X Leupold. The 1.5X is also quite fast, and I felt that I could place shots better with the Leupold.
In the woods, well..........., the red dot would have its advantages!
Something like the Eotech is probably the best of all worlds.