ADT is better than SimpliSafe in terms of smart home security equipment and monitoring. All ADT plans include professional monitoring not just for security, but for other types of incidents like fire and carbon monoxide leaks as well. ADT also offers a wider range of products that includes home automation equipment like smart locks, smart lights, and smart thermostats. And lastly, ADT has been around much longer than SimpliSafe. In fact, it’s the oldest security company in the U.S. today.