Hi Jodi,
I am so relieved to hear that Nina was alright,
I have a movement sensor Angelcare monitor, and James has stopped breathing in his sleep ONCE so far. I was able to rush straight in and once I called out his name he started breathing again. he has never had breathing probs at birth, or an other time.
James sleeps in the room next to us, so I dont keep the actual radio part of the monitor on overnight, but I do put the sensor on in his room,. Mine has the option of turning the "tick" off, but it will still alarm if it cannot sense movement within 15 seconds.

I agree if you have a large house, it is a very useful tool. I spent a lot of time outside, so I take the monitor out with me, so I can hear what James is up to.