At Bonsai Empire we receive questions about Akadama, and its use for Bonsai soil, quite a lot. With the recent price increases, troubles in supply and proposed alternatives (including cat litter) people seem to be in doubt wether or not to use Akadama at all.
Many factors come into play when trying to say anything sensible about Bonsai soil (climate, tree-species, stage of development of the tree, etc); this article generalizes some of these factors to not over-complicate the issue even further.