The main difference is the power: the ProX19 has a 2.0 HP motor providing maximum performance, while the X7 models1.5 HP motors power the X7 models. Additionally, the ProX19 sprayers come with a larger tip size range of 0.015" to 0.027", allowing for even greater control over paint application. In contrast, the X7 models have a more limited tip size range of 0.015 "to 0.021".