Here i made Aoto test where i show why.
I think that many Aotos are of very bad quality usually they are coarser then 1 k stone and have many inclusions and bad impurities.
Some of them are way to soft and need soaking before use and when you soak them they tend to crack or get lines.
I will say that 95 % of Aotos on the marked that i think very very bad quality. Specially new mindet ones.
And price = preferments is very bad
I will take good synthetic stone anytime instead of Aoto !
But have sad that there are also some very good Aotos that have very good speed and fines, feeling is also much better because they are much harder then bad ones, usually those Aotos are from old stock or vintage ones they tend to be very expensive too !
Here i made a test with some new Aotos and Vintage ones:
To compeer scratch patterns we start with Chosera 1k
Then red Akamom Aoto
Blue Aoto 2
Vintage good Aoto unknown
Vintage good Aoto unknown 2
Here is the video with this Aotos, Hakka and Hidiryama Lv 2
First is Red Akamom Aoto then Blue Aoto, Blue Aoto 2, Vintage good Aoto unknown, Vintage good Aoto unknown 2, Hakka lv 2, Hidiryama lv 2