The driver is a far superior binding, it has the same design as the STH 16 toe, just a lower DIN, and that makes it a more durable and more reliable binding, there is a lot of plastic on the STH 14, and the Driver streamlines that and replaces some of the plastic with some metal. The wings on the toe of the Driver are also better and prevents pre-releasing a lot better. The added weight is nothing compared to what you gain with the Driver toepiece.
with that toe piece, you get custom wing adjustment, and also height adjustment vs the quadrax toe(regular) with is automatic adjustment.
the custom adjustment give you a very secure hold even when your boot might be a bit worn.