Two-Way Voice on other systems works like a plain old speaker phone. You probable have the feature on your home phone. But with Two-Way Voice over GSM you have a much clearer digital signal that is transmitted over a cell phone. There is no way for a burglar to simply disable the Two-Way Voice but cutting the phone lines outside or by just ripping the control panel from the wall. Most burglars know that it is just that easy.
Guns and Dogs are great but unfortunately neither of them are a substitute for a security system. A gun will only protect you if you are behind it. Most home invasions occur while the home owner is asleep or unaware that there is an intruder in their home. In that situation most people are not likely to have their gun on them. Anyone who has a gun I strongly suggest that you have a dog or a home alarm as well. This will lessen the chances of a burglar catching you unaware.
When it comes to dogs you do have to mind the breed as some, though big, do not make good guard dogs. The best dogs believe it or not are smaller dogs. Large dogs tend to not bark. For instance look at St Bernards, Great Danes and Golden Retrievers. All 3 of these breeds are more likely to greet an intruder with a toy then to bark at them. Small dogs are more vocal but this can also backfire if they are too vocal. A Min Pin that barks every time someone walks down the sidewalk is just as ineffective because you will just ignore the barking. Best is to have a dog that is either trained or just has the natural characteristics of not barking too much but will bark at someone inside the home.
A home alarm can also provide you the for warning that an intruder is entering your home. Also with two-way voice your alarm will allow for the police to be called during a break in when you are not home. Most burglars will run when they hear an alarm go off. Those that don't will be heard over the two-way voice which will confirm a burglary is in process. This feature will protect your belongings and guns in the event you are not home.
