I have the TST 507 system on the truck & RV and am quite pleased with it. Because of the distance from the trailer wheels to the receiver/display unit, I did need the trailer repeater - YMMV.
I routinely air the trailer tires up to 120 PSIG without any problems. The big advantage of the flow-through sensors to me is the ability to air up the inner and outer rear tires on the truck without removing anything.
Rusty