I have the A1A and it has worked well for several years. Don't forget to register your warranty. That gets you into the battery replacement program where they send you new batteries and o-rings for your sensors every year for $5 in shipping. I have not replaced the valve stems on the toad with the metal ones yet. They are pretty short and seem quite sturdy. Have gone about 12,000 miles with no leaks or problems from the toad. I do have the Borg metal valve stems on the MH. I got a few "No sensor" alarms at first, but moving repeater from basement compartment to under the bed solved that problem.
Lost one sensor to what I think was a rock kicked up from the road, but the only thing damaged was the sensor. No marks on wheel or toad so I guess I will never know. Did not leak, just quit reporting to the receiver.
Have receiver mounted on dash and have never had a problem reading the display, even in bright sunlight.
1999 Newmar MACA 3796 F53 6.8L
2016 Ford Edge Sport
Roadmaster Sterling A/T with Brake Buddy Select