Tested out my new $15 TPMS system during today's commute, and I'm happy to report it works flawlessly. The sensors screw onto the valve stems and lock into place with brass nuts, hopefully preventing any loosening of said sensors.
Pressures reported match two separate analog gauges to a tee, and the temperatures reported were +/- 1° of ambient before driving. Pressures and temps rose slightly over the course of my 23 mile commute, just as one would expect. The sensors are serviceable, which is a great feature, and take 2x 1632 cells.