So you are speaking to a style similar to the false back aquariums only rather than back it would be side(end). More like a peninsula style. I imagine most enthusiasts would still hide the side sump and therefore feel it is a waste of display space. In other words... If you have a 48" long tank, why dedicate 72" of space. Most would opt for a 72" display and stick the sump underneath. Like you, I crave for more space above my sump... that will be my next tank. Sort of like having a 9' ceiling in the basement.