I think that the V2 USB Hubs are just for looks! They are NOT functional and there are many theories what they perform, for example a place to insert old USB sticks or USB wireless devices that will never be supported by SmartThings. Just like the promised Bluetooth capability that the V2 hub is suppose to has, but is not functional, nice to have it, but when not active, does it really exist? (See tree falling in woods when no one is there…)
I have the AD2Pi system connected to my Vista 20p home alarm system. The AD2Pi acts as a fully functional Vista alarm panel which can be programmatically accessed from within the Raspberry Pi.
I have developed a Python program that traps for all my home alarm contacts, IR motion sensors, smoke detectors and glass break detectors. The Python program sends a HTTP update to a SmartThings device driver for each alarm system event, effectively making all my Vista 20p contacts/switches/motion, glass, smoke detectors accessible to SmartThings to act upon via SmartApps. This custom integration saved quite a few $$$ and I did not have to duplicate costly Z-Wave devices on areas in my home where I already have coverage by the Vista system.
I also do not have to be concerned about the Z-Wave distance limitation is our large house, since the Vista system is hardwired to all alarm switches.
If the SmartThings backend cloud was halfway dependable, I would allow SmartThings to automate critical security routines based on events & presence, but that concept was thrown out the door when SmartThings V2 arrived and has made false positives and false negatives routine in my hub.
The Raspberry Pi is the master for my home at this point and it makes Home Automation decisions based on API’s to other presence services and can access the few Z-Wave devices I have installed from SmartThings and make decisions.