Never had a problem with the air-b, used them all the Ti,me as BitD* they where light and I liked the feel of them. They are a butyl/latex mix. Panaracer recently/still? Make some as I also have them I bought a year ago.
The problem with that Air-b is the seam has given way, probably not helped by being damn old. Dried up a bit since it was made
*There are now plenty of thin butyl tubes that are as light and lighter. Of course Foss and other similar are even lighter.
But there benefit I found was that they would cling around hawthorns like thicker butyl tubes, some thing thin butyls don't tend to do.