ADT is the largest home security provider in the U.S. with the most recognizable brand. But big doesn’t make ADT best. The over 400 reviews we’ve collected give ADT 2 stars out of 5, nothing to brag about. ADT uses a network of 400 dealers around the country – some better than others — who install and service the systems. Naturally, customer experience will vary. Top complaints point to high prices, up-selling and nickel-and-diming, poor customer service and cancellation hassles. One miffed customer wrote, “I will never use them again, I will see to it that no one I know ever uses them again.” Granted, company reviews often skew negatively, because satisfied customers rarely need to vent. Take a look at the reviews below and see what you think.