The actually air beams are a bit like tubed tyres with an inflatable inner encased in a tough, zipped, outer case. For one to puncture it’d either have to be faulty or you’d have to try quite hard to stick a pointed object into it. In normal use, so far, it’s not been an issue for me at least and the individual beams on the Vango ones at least are isolated, so if one punctures, the rest are still fine. They also tend to deform and spring back in really high winds rather than failing catastrophically like poles.
The big advantage isn’t so much with small tents, when really it just helps reduce pack size – as with the Nemo bevies – but with big family frame tents which go up really easily and in minutes with an air beam system as opposed to lots of pole-associated faff without.
I suspect they don’t fail that often, but when they do, it’s a pain in the backside, however broken poles in the middle of the night are similarly not exactly a pleasant, hassle-free experience.
Still, a potential god-send for those who love laughing at others’ misfortune even if it doesn’t happen very often. Tent for life etc, blah.