I have changed wheels several times on my Mustang. Last two times used the valve stem mounted TPMS sensors from American Muscle. One set would not train, I ended up calling American Muscle they were very helpful, said to let the air out, re-inflate wheels and they should train. That did not work.
I called the manufacturer , they said to remove the valve stems, let the air completely out, let the car sit for 10 minutes or so, re-install the valve stem and air. That procedure sounded weird but worked perfect.
Re training with the Ford tool is an easy procedure.
Definitely prefer the valve stem to the bands. We also own an Audi, it has a hub mounted TPMS with no sensors in the wheels at all. I wish all cars had this system, makes wheel changes much easier. Just install wheels/tires and its good to go, no re-training etc.
I like messing with wheels and would have bought an 06 Mustang if I had known about the federally mandated TPMS starting in 07.