I have the TST and after replacing the batteries I have no confidence that I got a good seal.
The o-ring is very fragile and I am concerned it could be damaged on assembly.
With the hermetically sealed sensor a leak which will cause a sensor failure is not likely.
I have caught two tires with nails in them by monitoring the tire pressures. I had time to get off the freeway once as I had notice a tire was in trouble before the pressure dropped to the alarm point.
Thus being able to glace at the monitor for tire pressures is a very big thing for me.
Also when there is an alarm a quick glace tells you what tire is in trouble. If it is on the TV then stopping is high priority. A Trailer tire may not be as high of a priority. The TST system requires waiting for the full pressure reading cycle before you know what tire is in trouble and what the current pressure is.
The Patrol TPMS will give you current pressure in real time on all tires. Thus if it is a slow leak you know you have time to look for a safe place to stop and as happened to me once time to take the next freeway exit.