I've not had any direct experience with ARE but I've looked at quite a few of them and they seem to be very well built. My Raven (built by Glasstite) was an awesome shell, very high quality. Based on price and number of features, I think ARE is near the top of the camper shell hierarchy.
However, I think if you are really serious about keeping weight on top of the shell, you might want to consider a Gemtop steel sheel. Expensive and heavy but very rugged!
Just from my limited experience I am not impressed with Leer. As I said above, the biggest positive of my present Leer shell is that it was dirt cheap and is adequate for now. But I do dream of a nice ARE with win-doors!