This time i conducted a small experiment.
I did two simultaneous brewings.
1: 180ml banko-yaki kyushu
2: 200ml glass teapot
I used 7g / 180ml 100C water in preheated pots.
3: infusions 45s/1m/2m
The differance in taste was clearly noticable.
The banko-yaki had a much softer mellower taste, with somewhat stronger aftertaste. The liquid was a bit more foggy aswell.
The glasspot tasted a bit sharper more fruity but with less aftertaste.
My conclusion is that banko-yaki isn´t a very suitable material for brewing black teas.