I don't have the AT3s, but I have Cooper S/Ts. I have nothing but good things to say about them. Coopers are still made in the USA and are owned by Cooper as well so this a plus for me.
I considered the AT3s but I wanted something with a little deeper, wider tread like the STs have. And the AT3, at least in a 285/75/16, only came in an E load rating, the STs I got are a D load rating. But that shouldn't be a problem for you since you are running stock size.
-2011 F-150 Lariat: 5.0 "Coyote" V8, 6-spd Auto (6R80E), 3.73 ELocker. White Platinum Metallic Tri-coat.
-1992 Ford Ranger: 4.0L OHV, 5spd (M5OD-R1), 3.27 Open.