QUOTE(sky_lor @ Mar 7 2008, 12:55 PM)
for the wireless alarm system, please bear in mind that there is some issue like batt life, not stable and so on...
I am all the while in this security and automation field. based on my experience is that even the landed luxury house we will still recommend for the wired alarm system. the reason why is simple because for wired sensor, it will be more reliable and maintanance free. for e.g: you don't know when the batt for the wireless sensor is dead. if you nvr change it and ppl break in, the sysm will not trigger.
the reason why they come up with the wireless DIY alarm system is target on budget user and want to save the cost on the installation charge. yes you can use it if you have the limited budget but please do test the system every month to see if it is still in working condition.
now a day alot of alarm system is coming up and it is not only working as alarm, but also integrated with other system like can control your light.for e.g: when the alarm trigger in the night, the sport light or the lights in the house will on.
Wireless has its advantages:-
Mainly home owners don't have to spend extra

hacking the walls to lay cables esp if the owners decided to install the alarm after renovating or have already moved in...
For the battery life span read the product manual, replace it once yearly.
The plus side if you decide to move you can take everything with you
Not to mention if you need to add extra sensors etc its also much easier... that my opinion anyway.
I still haven't decided to buy a home alarm yet