...No security alarm system PREVENTS intrusion. Alarm systems only report....
Very true. The plastic "this house has an alarm" sign does more for preventing an intrusion. Also good locks and proper lighting, already well covered under other topics already, does more for preventing an intrusion.
...Be sure to have a professional security alarm system installed and monitored to collect fully from your insurance provider....
Key word here is monitored. My insurance company gives a 2% discount for an alarm that makes a noise and a 20% discount for one that is monitored also.
I won't open up my entire soapbox on "qualities" of an X10 alarm as I believe a search of the forum will yield more than most want to hear again of my venting. I will say that one of the main drawbacks to a DIY alarm system, such as the X10 one, is that it is also a MIY
* one.
*Maintain it yourself one. i.e. DIY not only means
Do it your self but also
Debug it yourself.