I have quite a few of these Mr. Beams lights and I'm ordering more. Though you can screw them in or use stickers to attach them, I just put them on the floor or a window or shelf in the area I want lit up.
They light the way to the bathroom without being bright enough to wake up other people; they provide enough light in the bathroom for a visit, but not so much as to wake you up in the middle of the night.
I wouldn't say this particular unit is right for a closet. It's not quite bright enough for that use and it doesn't cast a broad enough beam. But it's perfect for path lighting and late-night bathroom visits.
We also use them in the room where we watch TV/movies via projector. If you have to get up and leave the room, these illuminate the way without interfering other people's viewing.
What distinguishes the Mr. Beams from a lot of other motion-sensing lights I've used is their sensitivity. They detect motion from a good distance away and from the side or front. They stay lit for 20 seconds after they stop detecting motion, and I've found that a good length of time.
Battery life is good.