I have a few monoprice motion sensors, they worked fine with Vera, but none of them are recognized by the z-stick. They don't even fail. The stick seems to ignore them.
Monoprice Z-Wave Plus PIR Motion Detector with Temperature Sensor, NO Logo http://tinyurl.com/y97yjs5m
Monoprice Z-Wave Plus PIR Multi Sensor, Temperature - Humidity - Light http://tinyurl.com/ydyhuohl