I am using 4 Sonoff motion sensors, with good results (2 hallways, 1 kitchen, 1 closet). Be aware that they lack features of, say, Hue motion sensors - no adjustment for sensitivity or timeout. Timeout is roughly 3 minutes, so if you were hoping to make a rule to turn off a light after 1 minute of no motion, then this is not your solution.
Take that for what it is worth, as I am rather fond of my Bosch sensors 
