Your Security level is not only about the equipment you have installed, it also how you use it. Most people who have CCTV fitted do not review it until something has happened.
There are two different types of burglars, one the opportunist burglar who sees an opportunity and grasps it, the other is the type who will make several visits to a property to way up what security you have and also what types of valuables you are likely to have, based on your make of your car, the type of furniture in the home right down to the TV.
If your home is flourished with expensive things like top of the range TV, Mercedes on the drive, and your home is kept in tip top conditions, windows cleaned and no grass growing out of the gutters, live bell box and cctv cameras on the outside, then the burglar is more likely to give your home a miss as they know that the Alarm is More Likely to go off and is probably connected to the police response or is monitored system, the cctv is working and constantly recording.