Autolocator stands were initially created to give studio engineers an easy way to mount their tape transport controller (Rec, Play, Rewind, etc.) at a convenient height and angle. Roller wheels made it easy to drag it along as you moved across the mixing board. Today, many mixing boards and control surfaces have built-in transport buttons.
But it turns out that these stands are staggeringly useful for other devices as well. I, for example, play a strap-on MIDI keyboard into a Kurzweil rack module. An autolocator stand holds the module at the perfect height and angle to make adjustments while I’m playing, without having to turn around and reach down to my rack. If you use a horizontal MIDI controller keyboard you’ll find that it’s much easier to tweak your synth module when it’s right behind your keyboard and angled conveniently.
Guitarists will also appreciate being able to tweak their tone on a Boss GT-Pro or Line 6 PODxt Pro without moving from their position. And “groove box” performers will find that they’re now free to move around the stage as needed. Try one and it’s likely that you’ll find a need for another.