These are great simple controllers for a 12-channel rig, or as an auxiliary desk for running effects outside of the main DMX ring, such as strobes or smoke machines that you want to keep manual control of.
We have one of them installed in a small drama space that has a 12ch generic rig, and we have another of the 6-channel versions that we use as a simple controller for strobes or smoke machines when they are used on their own but want remote control.
It's helpful for non-technical users as it just turns on and works. Can run off a 9V battery as well.