I have an ARO here, as well as a ProTank and a MT3. The thread diameter of the MT3 is a little smaller than the inside of the ARO, so the T3s base won't fit it, being the T3s is the same thread as the T3. The ProTank coil will screw into the ARO base, but there's a little shoulder on the ProTank coil that's a hair bigger than that of the ARO coil and doesn't allow the base to reach the threads. It looks like the inside of the ARO could be Dremeled out to allow it to take the ProTank/T3s coil. The ARO coil works and vapes just fine in the ProTank, so it looks like that shoulder is the only difference between the ProTank and the ARO coils.
Incidentally, the ARO hits just like the Protank and the ProTank Mini. The glass tank doesn't affect the flavor the way a plastic one does, so all you get is your juice. I don't know that I'd ever vape out of anything other than glass again... Spoiled, I guess..