We bought the TST 507 as well and it's great. Easy to setup and install, and they have a 7 day a week troubleshooting # you can call with issues.
We did need to have longer stems installed with a holder for the end of the stem, so they didn't bang around. Makes it MuCH easier to fill tires as well, so it was worth the cost (kit and labor was about $175 at our local tire chain)
2015 Georgetown 351DS
Chris, Garren (humans)
Edgar & Carlos (felines)
RIP Sophie, the sweetest cat ever.