I took a 3600 mile trip in July/August and had 5 flats along that adventure; all on those were on the rear tire. Although I run tubes in my wheels, my tires are tubeless tires (Heidenau K-60s) and they are a pain to break and reset the beads. So in September I took another 1500 mile trip and bought a set of these to see if it'd make the trail-side tire changes easier. While I am anxious try them I can report that there have been no more flats!
So maybe it's worth it to buy and set and then not have to use tthem?