Good motion sensor

The Bosch ISW-ZPR1-WP13 motion detector is only $12.99 right now at I saw a bunch of conflicting reviews about integrating it with HE, but for the price I had to try one. For me it works perfectly, and it's a nice piece of hardware.
At first I though it wasn't sensing consistently, but it turns out there is a 3 minute delay between trigger events. Once I learned that it has worked as expected every time. There is a red LED that only lights during a "walk test", where you walk around the room to test sensitivity in different areas. When in normal use it never lights up.
This thing is so good and so cheap I might get an extra one to keep in reserve.