You might want to take a look at the Valor system. Probably a little more expensive but it is a banded system that fits inside the wheel.
I dont doubt that the TST system is good with air pressure but I'd rather have the temperature of the actual hub as close to the hub as I could get
I do believe it is good to monitor air pressure and a few have reported knowing the air pressure has saved them but if a tire is going to blow it is going to blow with little warning.
To me the most important part of these systems is temperature to watch the bearings and being right at the hub is so much better than wagging out in the air