If you are a young driver looking for insurance, taking out a black box insurance policy is one of the surest ways to save money on your cover, requiring you to simply drive carefully and responsibly, and enjoy reduced premiums as a result.
You may need to wait for a year or so for your premiums to go down, as the insurer needs time to build up a profile of you as a driver, but once they do you can expect rates reduced by a third or more.
However, if you feel that you are likely to have a particularly high annual mileage, or to drive often at peak times (which will be defined by the individual insurer), then a car insurance policy without a black box might be more suitable.
This is often the case for experienced, middle-aged drivers who are likely to experience low premiums anyway and are thus not particularly likely to benefit from telematics technology.