Yes, security systems are worth the money, if the system you purchase is actively monitored by a certified company.
Even if you have smoke alarms in your home, the smoke alarms cannot call the fire department for you. What if there's a fire when no one is home? Then there isn't anybody to call the fire department for you, because the neighbors won't be able to hear your smoke alarm. No one will know what's going on and call the fire department until they see smoke or flames. By that time your house has sustained extremely serious damage, and who knows how much worse it will be by the time the fire trucks arrive.
A smoke alarm may wake you up and give you the seconds you need to get out of the house. But then you still have to call the fire department. Are you going to stop to make a phone call from a burning house? What if you forget your cell phone in the house? Then you have to wake up a neighbor to call the fire department for you. In many places, when you call 911 on your cell phone you are connected to the Highway Patrol emergency dispatch service, and you have to give them the address because it doesn't come up on their equipment. How many seconds or minutes are wasted if their dispatch center is not local and they give your information to the wrong fire department? It has happened, more times than you'd imagine.
Wouldn't you rather that the alarm system monitoring company has called the proper fire department on a direct line phone number as soon as your alarm sounded, so that you can concentrate on the important stuff, like making sure everyone got out and they are safe?
If your alarm system is just a bell or siren that goes off, people will ignore it. Just like car alarms. You want to have a monitored system that contacts the police or fire department for you.
I don't remember the exact statistics, but the odds of being burglarized go way down when you get a monitored burglar alarm system. Think about it... if you're a burglar looking for a house to hit, would you select the one with the alarm that you know will sound an exterior siren, set off an exterior strobe light, and dispatch the police? Sure, you might have a couple of minutes before the police get there, but as a burglar, wouldn't you rather have lots of time in a house with no alarm so you could spend your time looking for the best valuables to take?
Most burglars leave right away when they set off an alarm, so the homeowner's monetary loss is usually much less because the burglar is under pressure to grab something and get out quickly before the police arrive. How much do you think you'd lose if a burglar had 4 hours to leisurely search your house for everything valuable in it, and destroyed many of your belongings in the search or just slashed all your furniture, clothing, and bedding out of sheer vandalism?
Many alarm systems have the capability of allowing the monitoring company employees to listen in when there is an alarm. They can often hear the burglar, and report to the police that they have verified a burglary in progress. Don't you think the police are going to race to your home to catch the burglar in the act faster than if they got a call from a neighbor saying your siren is going off and the noise is a bother? Sometimes the alarm monitoring company can even announce to the burglar through a speaker in the alarm panel that the police are on their way. Don't you think the burglar would leave quickly?
Is a monitored alarm system worth the money? Homeowner's insurance companies certainly think so. These insurance companies recognize that monitored alarm systems reduce the number and amount of the claims you're likely to make against your policy. So they reward you for having that monitored system. Some insurance companies offer up to 10% discount for the burglar alarm and up to an additional 10% discount for the fire alarm. Depending on how much you're paying for your homeowner's policy, these discounts could pretty much pay for your monthly alarm monitoring fees. Some alarm companies will even pay your insurance deductible up to a certain amount if you suffer a loss while their system was activated and protecting your home.
The home alarm industry is extremely competitive now, and many companies will install a basic system for no equipment charges, just a contract for monitoring for a couple of years. Find out the offers from several different companies. Don't just pick the lowest monthly monitoring fee; pick the company you can trust who offers the best equipment and service package to suit your needs.
Another thing to consider: you probably don't want to go with a company who has a single, local monitoring center. If there is a disaster that occurs in your area, like an earthquake or hurricane, the company's monitoring center will probably not be fully staffed because their employees won't be able to get to work. They should have a monitoring center out of your immediate area, or multiple centers with the capability of sharing the monitoring load between the centers, so they won't be affected by any local disasters.