I have the TST system on my current RV and had it on my previous one too. I have had trouble with their flow-thru valves, but I find the non-flow through ones to be rock-solid.
Generally speaking, this seems to be a "young" industry, and the technology for making small, reliable, portable valve stem "caps" that will transmit PSI and temperature must not be that reliable. I make this judgement based upon the numerous forum members who have issues with their systems--nearly universal among brands. AND... if it were easy enough, I think RV Manufacturers would be installing them on even the most entry-level RV's. I don't think they do this because, in part, they don't want the hassles.
Having said that, the people at TST are very cooperative and eager to provide customer service. Their system comes with a 3 year warranty, and they are more than happy to provide replacement sensors when you have problems. They replaced several flow-through sensors for me, and I had other issues that ultimately resulted in them replacing my whole package. I gave up on the flow through sensors and just went with the (less convenient) caps that you have to remove when adding/removing air.
With the replacement unit and non-flow-through sensors, knock on wood, I am doing alright. I run the system with TWO signal boosters--one mounted inside my Toad, and the other mounted close to my passenger/rear tires, where I happened to have a 12v power supply.
2013 Fleetwood Discovery 40G, Cummins ISL,Freightliner Chassis, Allison 3000.
2017 Ford F150 Lariat toad w/
Blue Ox Aventa tow bar and M&G Braking System