I have one on my van and always thought they were more of a pain then they were worth. Then a couple years ago we were coming back home from dropping my daughter off at University and hit a board laying on the road. A minute later off goes the alarm and I pulled over, the tire emptied in less than a minute and by pulling right over I saved the tire. My daughter on the other hand does not have TPM and she was driving her car and got a flat and by the time she noticed it the tire was shredded.
Decided that I will be adding to the camper soon just for the extra piece of mind.
