TIM wrote:
Interesting Tead off, would you explain more about how Duanni clay is not known to enhance flavor and aroma like the other clay? And what doesn't it offer to your brew besides good looking. Thanks -T
Tead, In your response, you quote personal experience and views of tea masters - if their words and your experience are based on generally found and repeatable practice then none of us should be buying anything other than Zhuni and Zi Sha.
The problem is that so many good vendor sites, and erudite tea bloggers do express value to be found in some of the other clays.
A second problem that a short phrase that uses the adjective 'better' can perhaps be misleading.
I have seen the 2 following phrases quite often -
a) Zhuni (or Zi Sha) is better for Yan Cha (or Dan Cong)
b) Ben Shan (or Duanni) is better for Anxi or Taiwan oolongs.

better than what, for what, in which way is usually omitted.
would a) mean Zhuni is better for YanCha than other clays are, or better to be used with Yan Cha than with other Oolongs.
would b) mean that Ben Shan produces better results with Anxi than it does with Yan Cha or does it mean, Anxi is better with Ben Shan than it is with other clays.
Your advice suggests how I should be interpreting the statements.
Fortunately, I do not have a dilemma, my taste buds have yet to develop the level of appreciation where this would matter, as the other variables in play (water, humidity, atmospheric pressure, personal emotive state of mind) tend to show even larger differences in the end brew.
For now, I have allocated my :-
Zhuni (and reddish Zi Sha) to YanCha
Zi Sha that is purplish and dark brown to DanChong
Yellow Division Clay and similar (which will include Duanni when I buy) to Anxi
Ben Shan to Taiwan
Hei Ni to Pu Er
I have been very pleased with the results.
maybe 1 day when I am further along the path of tea I will want Zhuni (of great age) for all and every type of tea I drink, but for now I am content to allocate accordingly.