The main differences between these models are their capabilities and specifications. The W5 Tiltmaster has a GVWR of up to 17,950 pounds and is designed for medium to heavy-duty applications. The W6 Tiltmaster has a GVWR of up to 25,950 pounds and is built for light to medium-duty applications. The W7 Tiltmaster has a GVWR of up to 33,000 pounds and is designed for heavier loads. Additionally, each model has different features and options available, such as engine choices, suspension systems, and cab configurations. Overall, the main differences between these models lie in their weight capacities and intended use cases.