Tamesbm,
The thickness distribution, material, shape, and size, of the tea cup influence greatly the taste of the prepared tea infusion. I think you have made a discovery before you made your posting here a few days ago. If you actually compare it, the difference the cup can make is (much) greater than the counterpart (the glass) can do to wine.
Porcelain and ceramic are the best materials we have experienced so far, but it all depends of how well they are made for tea drinking.
