I carry the Sears compressor in our Sundance (thanks to the many recommendations on the forum), and make it a standard practice to check the tire pressure on the 5er and TV before traveling. I will do this daily if needed. It only takes a few minutes, and topping off with air if necessary is no big deal. It is the cheapest insurance for care of the tires.
The tire pressure monitoring system is on my wish list, as well as replacing the Mission tires I presently have.