I have had the Doran system for about 3 years now. I added the option antenna underneath and to the rear of the motorhome and have had no signal trouble.
While it is a bit of a bother, when parked at home or at a camp ground, I always remove the sensors from the valve stems. This saves or extends the life of the internal batteries and prevents someone from stealing them.
04 Winnebago Sightseer, 35N, W22 Chassis
Amateur Radio - WB2LOU
Education is the only legal cure for Ignorance. The Stupidity of many is incurable.