I love the look of a shallow tank, they are great for growing emersed plants and creating a full biotope from bank to water. I have one that is only 18cm high and 2ft long. It has no plants, just big chunks of Malaysian driftwood jutting out and moss growing emersed on parts.
I wish there were more shallow (and rimless
) tanks out there. The only problem with mine is sometimes my plakat male jumps out when he sees me coming with food. But I just drop the water level to about 10cm or so.