Baby Monitors: Movement Sensor Or No?

Ko
I read a really great review for the Angelcare monitor with the sensor a few months ago, and I was totally sold on it since I'm a FTM. However, now I'm wondering if it's worth the high cost. We live in a small house and I work from home, so I'm considering the Summer Infant monitor now. 
Does anyone have any opinions on having that movement sensor? Is it REALLY worth it?