Ye I've used them and they definitely do prune as advertised. However, a lot depends on the size of the container; as to whether you'll gain a benefit or not. If a plant is in a container long enough to become root bound and slow growth; then the same age/size plant in the Air Pot will still have room to grow from auto-pruning and thus get larger. If your not @ root binding point by the end, then it would be hard see much difference.
What I consider the most important with airpots; be sure that you start young plants /cuts in their smallest size (e.g. 1L) to "Setup" auto pruning at a small age. If you take a root bound and spiraled plant from a cup and put into an air pot, in general, you will not see a big difference.