Battery life on the Pressure Pro sensors is about 5 years, but many folks get six or seven years out of them.  We have both Pressure Pro and TST.

TST has more options.  You can get the sensors with replaceable batteries (you have to replace them about once a year) or you can get sensors without replaceable batteries (like the Pressure Pro).  The TST system does monitor temperature, but with the sensors on the outside of the tire, that's not all that great a benefit.  Pressure will also rise with heat, so either system will notify you of extreme heat problems.  Their newest feature is the flow-through sensor that allows you to add air without removing the sensor - I have no personal experience with those.

In my opinion, the Pressure Pro system is easier to install and program, and they probably have the highest rate of success over time of any pressure monitoring system for RVs.  However, Pressure Pro is pricey and the replacement of your sensors every five to seven years adds to the cost.

TST is less expensive and you have multiple sensor options.  Tinkerers will like the replaceable batteries (a glorified watch battery) while those that just want to put the sensors on and forget them will prefer the non-replaceable battery sensors.  One thing that made installing the sensors difficult for me was their anti-theft feature requiring the sensors to be installed with a special wrench.  In our case, there was barely enough room to screw them on by hand, so having to install them with a wrench was frustrating.  If I were ordering a new set of sensors, I would forgo the anti-theft type and get the ones with ridges that you can screw on and tighten by hand.

If I were ordering a tire pressure monitoring system today, I would only choose between Pressure Pro and TST.  Personally, I prefer the ease of Pressure Pro and have been pleased with the performance (until the batteries wear out).  But for a less expensive alternative with more sensor options, TST is certainly an excellent choice.