Once the pass code is changed you will have full access to the service menu for diagnostics, etc. The service laptop costs around $1,000 with the cables included. You also will have to buy a perpetual license for the software. All the laptop allows you to do is update software when installing a new model or change the password, both of which is a separate license.
The laptop does not have any additional tools for diagnostics, that is fully included in the access 1 software already installed to the truck.
The access 1 is basically the diagnostic tool unlike a car or other brands where you so need a separate controller.