Petr Novak's Tea-ware, Clay, and Teas

[ShuShu]

I have recently succeeded to put my hands on one of those dark, unglazed, and iron-rich gaiwans/shibos by Petr Novak.
Was just wondering if anyone here experimented with his pots/shibos and can say how it performs with different kinds of tea?
I hear people use it for Japanese greens? perhaps aged sheng? What kind of effect his clay has on tea?

[Teachronicles]

I have recently succeeded to put my hands on one of those dark, unglazed, and iron-rich gaiwans/shibos by Petr Novak.
Was just wondering if anyone here experimented with his pots/shibos and can say how it performs with different kinds of tea?
I hear people use it for Japanese greens? perhaps aged sheng? What kind of effect his clay has on tea?

I have one of his shibos and haven't tested side by side with porcelain so I can't say what effect the clay has specifically, BUT, I use it for shou and it retains heat much better than a porcelain gaiwan, so I think they work well for shou, aged sheng, aged oolongs, stuff that likes a lot of heat. I actually got a few items in his last tea club selections and am planning to use one of the pots for yancha, because of the heat retention and extremely quick pour.