It's worth it. It may be standard on the 2007's, as required by U.S. law. At rest, before running the car, you can get a measure of whether or not the tires are at pressure by using the computer control to enter the system.

The pressure readings that are normally displayed by the computer give reliable readings of the tire pressure only when the car is in motion.

Finally, you would get a warning if the pressure falls too low, thus preventing damage to a very expensive wheel.

Most of this is explained in the owners manual, although in a somewhat roundabout way.

Jim