I have a 110 high (48 x 18 x 30) and find it limiting in terms of what can be comfortably kept in it, although it looks great as a display because its height. Currently this tank houses five orange-head Tapajos, a threadfin acara, an orange-cheek Krobia, and a school of bleeding heart tetras. That works fine, but I wouldn't keep larger aggressive cichlids in the tank, at least not as a community (a pair of med-size fish is a different story). Although the tall tank you are thinking of has a larger footprint than what I've described, I'd still balk at the short length when a 6' tank is an alternative. If you want bigger fish that can mix it up once in a while, definitely go for the extra length of the 180. Although the difference in volume may only be 30, the 180 has a lot more space for aggressive fish to avoid each other. I keep larger CA cichlids in a 6' 210 gal and can't imagine the community working in a shorter tall tank.