Pros: passive infared technology - sounds cool and helps keep unnecessary electricity use to a minimum
Cons: possibly installation and price
As I am still not sure on the price of the product or the installation process, this review is not the most complete...however:
There is always that moment, when you are lying tucked in bed and you notice that the lighting your hallway or your kitchen (which is 10 feet farther) is still ON! We all know that the "right" thing to do is to pull yourself out from under your warm covers and to push every switch to its off position.
How great would it be to have a device that not only turned your lights off for you, but better yet, turned them on too. Seriously, the Manual-On Occupancy Sensor seems like a useful and sensible tool. It is space efficient, not bulky at all (looks as if they lay flat to the wall and fits into a standard wall box), and depending on which model you buy it comes with multiple settings from a Manual On/Off feature to various OFF timers (10min, 20 min, 30 min). It even has a feature that prevents lights from turning on when there is ample natural light in the room.
Whether renovating your home or moving into a new one, I definitely think light sensors are an addition worth looking into.