I have an ARE on my '16. Bought it used this spring and was told it was originally on a '12 model...it's in really good shape for the age but don't know the history of it (parked in a garage or outdoors, etc...). It has the prop open windows on each side and the factory option tool boxes, along with LED lights for the side boxes and the tailgate hatch that are on prop switches (turn on when the windows are opened). Fit and finish seem decent. The bottom rails on the cap kinda' have a lip that fits over the bed sides to line it up side to side and front to back. All the latches and hinges work good.
There are different models out there that I think look a little better, mainly because the side windows on the cap match the side truck windows in regards to being the same height. Don't think this one looks bad though...........especially for $550.
The tool boxes and flip up sides windows are really nice to have. Took the family on vacation this summer in the truck and it's really nice to put the smaller luggage and other frequently used items on the sides. Makes it way easier to access those without digging through the entire bed. Obviously helps organization. We worried about room for bigger items in the back but it hasn't been an issue because the boxes really don't stick inwards further than the wheelwells. Never removed them but looks fairly easy with a few bolts.
The lights on the prop switches are a must in my opinion. So nice to just open the hatches and the lights come on.
The front cap window is a slider, and the truck has a rear slider, but I've never had the cap slider open.
Would like to have it carpeted/lined inside as my plans are to sleep in it every once in awhile (did in my old truck) but not a huge deal. The other big thing that would be nice to have is locks that work with the truck FOB.