I used American Theater a couple of times 3 or 4 years ago and had a couple of problems, a sorround speaker that didn't work, but they quickly replaced , and a Sony ES CD mega changer
that ended up taking a couple of months to get, but by far and large, they treated me well and their prices were great.
I really didn't know that they were still around. Their website fell into neglect, so I assumed that they had folded their tent.