I just want a more modular system. I already have the MaxiSYS Ultra as a diagnostic scanner. I want to add the KM100 to my line up of Autel tools so I just want to make sure it will work with my system. I know the XP400 Pro is a more powerful system and it would be cool to be able to just pair that individual tool with my KM100 so I can have a separate Diagnostic tool and not need to carry a much larger system with me. I love autel and their line of products. I want to be able do key programming for myself more than anything.