I just purchased a Burris RT-6 to sit on my Barrett Rec7 AR-15 for coyote hunting and so far, I am VERY pleased with it. It is very robust and has survived some rough treatment out in the desert (I already dropped it, climbing over a fence- checked zero and it was spot-on).
The illumination is very good- not daylight bright but perfect for me for coyotes, before sunrise, when I need illumination. There is a bit of fisheye at 1x, but it's only on the edges in mine. So far, for the money, I believe it is an excellent value. Just as a disclaimer, I have no experience (and therefore no opinion) on the Arrowhead. Best of luck in your search.