[The Newell]

IMHO the best thing you have done is to decide to get them. Research them and decide which one you want. While I have them and I am satisfied my recommendation is of little use as I have only tried the system I have.

Some of the things you need to decide is
1. Do I want them mounted inside on the rim
2. Do I want to monitor temperature and if so what temperature is the device measuring, the air around the valve stem, the rim or whatever.
3. Do I want to be able to replace the battery in each sending unit and if so what does that do to performance.
4. Do I want real time monitoring of the the pressure in each tire.
5. Do I need a repeater so the device will monitor the tire pressure that are the far from the receiving unit
6. If I can not replace the battery can I get replacement units at what cost and how long do they last.