Here is my limited teapot collection:

From left to right: ZhuNi from Stephane (Tea Masters blog), Banko, wood-fired natural red clay from Petr Novak, and two Shigaraki teapots.
What makes Shigaraki teapot special is not only the clay properties but also the firing technique as well. Made out of rough clay, this teapot is very porous, and thus highly interactive with the liquor.

It took me literally three sessions of brewing the same tea to get this effect. Not only that, the tea aroma would absorb into the clay and each time hot water is added, I can smell it from the clay. But flavor and aftertaste is what the Shigaraki teapot shines. I dedicate one Shigaraki teapot to Hung Shui Oolong from Stephane, and not only the flavor is more pronounced compared to my ZhuNi but the aftertaste is significantly longer. It stayed in my throat for almost an hour.
Overall, I'm quite happy with what I got so far. These fine teapots can only obtained from Hojotea at the moment.