I have wondered if a low water level riparium would work best without aquatic plants. It isn't like you need the plants to keep the water from containing too much nitrate for the fish to live with. The emersed plants will be using it up rapidly anyway. And, the shade down there isn't conducive to growing most aquatic plants. But, with a high water level, and the plants growing out of the top of the tank, it might look odd without the aquatic plants. I'm still thinking about what to plant in my new, high water riparium.
For those with hard tap water an aquascape consisting of rocks only would be a good thing to try, and it would certainly be ideal for many cichlids. But, my tap water is very soft.