We have the Presure Pro system for six wheels; however, I have not installed it yet. Based on other user reviews and my own research, I picked this system for its ease in installation. The only drawback I see, at this point, is that if I need to adjust the tire air pressures, the tire sensors must be removed.
I will have a better assessment once I have used the system.
I'm in the process of orderering one of the PI PT50C Surge/Voltage regulators, and do not have any direct experience with one (sorry). Please keep us posted on the new unit once it is received and plugged in.