As hanny93 has already written, it could work really well for a group of six Angelfish with all that depth, which is also appreciated by Brochis catfish (especially B. multiradiatus). For the top, perhaps a nice big group of one of the bigger hatchetfish, Thoracocharax stellatus? Alternatively, a Tanganyikan setup including a smaller variety of Cyprichromis (open water swimming fish) could work well, giving these sardine-like fish plenty of water to roam in, out of the way of some shell/rock dwelling species.
Even though a lot of fish are said to occupy certain levels in the water column, very few of us have tanks with enough depth to truely represent this at home, which this tank sounds like it might do wonderfully. At the end of the day, your dilemma on this tank will come down to what stocking you have in mind and whether you are the type of fishkeeper that often swaps and changes its occupants.