lets see how do i put this--
it has an advantage over terracotta in one way i know and it depends on your frame of mind.
how do i explain in an American way-- well the purple clay has the advantage of location location location. you see i have found a purple clay here in the US and it has the same properties as the China one so i guess the terracotta is a close match too. but they are not exactly the same. if i told someone that the pot had purple clay in it then visions of China come up and if i tell someone it is terracotta then visions of Spain might come up and i bet if i told someone it had stuff in it like Georgia pine then visions of the great state of Georgia would remain. so you see its all pottery but were do you want to be reminded of. It can all boil down to the Qi " too to use a Chinese word" or energy/power which is in the pots. all of them are made of earth then subjected to some sort of fire.
so i guess a good question to pose now is " were of earth do you want your pots born of and what do they do to remind you of your time there?"
and yes all the pots i make glazed and unglazed are the best type to use to store tea in here in Colorado.

i even just made some for water too but waved the magic pottery wand and now a few are for tea.

and get this they are of stoneware
all jokes aside i feel it is all up to you which type of pots to use but it is best i think to use a pot " be it big small etc" that will give its energy to the tea and in turn ultimately to you. you see everything has a part in what you do so if you take advantage of the things close then the energy you get from them will be of a type you can appreciate and relate to and then pass on to the next......./