I worked in retail and higher-education for a number of years. I saw sensor lights used well and poorly. If tuned correctly and used correctly, they work very well.

Good: sensor lights in walk-in coolers and bathrooms at grocery stores seemed to work very well.

Bad: sensor lights in some classrooms led to some really frustrated profs and a whole class spontaneously, and simultaneously, waving their arms.

I've been contemplating trying them out for my kids' rooms.