I agree that their subs look on the weak side compared to other ones. I have the EP125 (their smallest model), and, no, it does not go super deep. It is, however, one of the fastest, most musical subs I've heard for the price I paid (490 CAD). It's not the least bit boomy or slow.
I would, however, like them to combine these traits with a sub that can hit it out below 20hz, to really make my pants shake when listening to it. I was also disappointed that the Line Level In does not have gold plated RCA jacks. Perhaps these are two suggestions that should be incorporated in their next design!