The Path Pro bills itself as the ultimate golf training device. By positioning the adjustable arm, you can work on a variety of swing faults, including swaying, lunging, getting trapped, and over swinging. It also can help you maintain balance and set for proper impact.
To be honest, you can do a lot of the same drills with a chair or a wall, or a few extra club shafts. But are you really going to carry a chair to the driving range?