If it's for home automation, those motion sensors will do. I have an Elk M1, which can interface X10-RF using the W800RF (RF receiver for X10 hardware), and allows me to use my X10 stick-on-wall
switches , X10 motion sensors, DS10A door/windows sensors and some other gadgets. The X10-RF hardware isn't bad at all (IMO) as long as you understand the limitations.
I just cannot get these motion sensors to act reliably! Assuming I just totally start over what are my options for any system? I am to the point where money is not an issue or I am just giving up. Worst case would two redundant sensors work reliably?