Quite an interesting read. The fact that Aquasoil has nutrients packed in its soft clay granules makes Aquasoil a great substrate above others like Eco Complete or Flourite in the initial stages. I'm not saying that you can't have great aquascapes with the later basically inert substrates, because you can, you just have to do more regular fertilzing then say a tank with Aquasoil.
The below Lab experiment is a bit misleading since you can/should supplement your water column to make up for the lack of "stock" nutrients in inert substrates, but the Lab experiment does show you that Aquasoil does have an advantage in that regard, especially in new setups.
Grossostigma was planted in Aqua Soil - Amazonia and Forest Sand - Branco
Grossostigma after 10 days
-John N.