Baby Monitors - Help?

We have our pads under the mattress as thats what the instructions said.

I have an agelcare but i dont bother with the movement sensor i only use the sound (I got it off trade me for only $50 so figure i can sell it for more later!). personally i think the movement sensor is abit of overkill. my baby was very premature but once she was off the monitors int he neonatal unit they didnt put her on the movement sensor after that for the next 3 weeks she was in there (some other babies did have them as were more risky), so i figure if she didnt need it there she wouldnt need it at home. all i hear of with people who have them is the monitors going off when the baby is abit older and wriggles up the mattress! but peace of mind is always a good thing as a parent, so if it is something that will help you sleep better at nite, then by all means spend abit extra and get one, anything to help us sleep at nite! then again if they are sicxk the movement sensor might be a good thing if a bad chest infection. up to you and how much you worry about things