I bought the TST system last year and have been very pleased. Being new to RVing with a 33' Class A and a toad I unknowingly overheated my brakes on a long downgrade. I learned about my problem when the heat sensor alarm went off in my TST pressure/temperature monitor. I was able to pull over before any harm was done. They also alerted me to a very slow leak in the valve stem on one of my inner rear duals So yes, I'm very pleased.
I currently have the inexpensive ones, when I replace these in a few years I'll get the ones that mount inside the tire.