We have used the Tire Minder system for 7 years. It has alerted us twice that required attention, Awesome. It was not fast enough to alert us on a tire tread separation blowout at 65 on the highway, Not so good. It has alerted me falsely twice, worth a manual check. It is just another tool in the box. I still check PSI before trips manually.
I do check the tire status often while on the road and check temperatures as well as PSI. Only you can decide if the $ is worth it. I felt it was. Just do not count on it by itself. A high quality PSI gauge cannot be beat.
Greg, camp chef.