I have a Stag Model 4 and it is good. The charging handle is a little fragile and I upgraded that. Very solid gun. Two friends have model 3s I believe...and one of those guys shoots 3-gun...lots and lots of rounds. He is happy with it.
Stag makes a good AR. Best is a rather subjective thing. I chose Stag based on first hand experience with friends, the availability of the Model 4 which is the M16A2 style 20" barrel, fixed stock model, because of good LGS is a Stag dealer and has stock handy, and for the reasonable price.
I have never seen a Colt's for less than $1200 around here. While I am sure folks are not lying, there seems to be this idea that there are $900 Colts to be found...haven't seen it. Same folks who talk about the $600 lower end ARs and the nice, inexpensive old revolvers...don't see them.
You will be happy with Stag I'd expect.