I have to admit that I don't think any of these systems would work like you all want them to in real camping situations, but just assuming that they would... I'm very curious:
What are all you guys planning to do when the alarms actually go off?
A. Hope that the hungry (and highly food motivated) wild animal(s) (that are probably not bears, by the way) will be permanently thwarted and won't find a way around the "security system" the second time around in a half an hour when you are sound asleep again?
B. Get out of your sleeping bag (10 seconds), get dressed (20 seconds), put your shoes on (10-20 seconds), get out of your shelter and, in the middle of the dark, try and locate and chase said animal away?
I'm just not seeing the end game here.