Personally I wouldn't be without it!
I get serious peace of mind from seeing the heartbeat ticker when I wake up in the night or I'm downstairs in the evening. Mine does video too so I can see what's happening.
Tbh if it's properly installed I don't really know how the wires would get caught up? Maybe if the child is older but no way a baby could pull back the crib sheet over the mattress and then slide the sensor out..but for the first 6 months or so it def gave me peace of mind. The wires come right out of the bottom of the cot underneath so they would have to have the strength to sit back on the mattress and pull the sheet and mattress up to et the wires up, plus the monitor part on the other end wouldn't fit through the bars so that would have to be unplugged too.. I would say its incredibly unlucky that would happen.
I'm not a worrier but when dd was in her own room I used to go in and check on her all the time as I was worried she had stopped breathing for no reason! On mine you can see the breathing rhythm and heartbeat, it's the angelcare one.
Def wouldn't work or be much point if you were co sleeping, I agree there. Yes it does give you a fright when you go to pick them up in the night and forget to turn it off! Have had hubby run in many times in a panic lol.
But at the end of the day it's down to you, if you are planning on having baby in your room for a few months and you would be happy without it then there's no need. I feel a lot happier with it, you can pick them up pretty cheap at nearly new sales or on eBay, it just gives me an extra bit of peace of mind for the first few months but I wouldn't carry on using it long term for years etc