At the risk of getting into a religious ;-) argument over soils...
Here on the east coast (and Gulf Coast), ingredients that seem common and inexpensive on the West Coast can be extremely hard to come by not to mention very expensive. Akadama, when you can find a reliable supply, is roughly $40 for 30 lbs or so. Pumice in smaller granule sizes is mostly unavailable--or about the same price as Akadama. Same for decomposed granite...While all of these are readily available in Cal., since it's 3,000 miles closer to the source, or in the case of decomposed granite, it IS the source.
If you live in the Mississippi Delta in La., or in East Texas volcanic rocks (or ANY rocks) are not all that common. They have to be trucked in.
Unless we Easterners are potting a really special individual tree, or a bunch of small trees, Akadama and pumice isn't usually in the cards. I know if I potted all my trees in a mix of either, I'd spend A LOT of money that might otherwise pay my mortgage.
That leaves what works and what's not hugely expensive--turkey grit, swimming pool filter sand, baby orchid bark (I understand about inorganic mixes. I've tried them. They work, but there are issues with them--they dry out EXTREMELY quickly. A windy day can cost you a tree or trees if you've not around to keep up with watering...), haydite, composted pine bark are all available at low (er) cost than pumice and Akadama. All work pretty well, at least in the 15 years or so I've been using them.
I know all you Californians and West Coast bonsai folks roll your eyes whenever some Easterner says this, but, bottom line, the East Coast isn't California--or Japan. We have a climate (s) all our own, from Florida to Maine and from Illinois to Texas, it's pretty diverse. What works one place may not work in another...