Loki,
In a world with tens of thousands of different teas, ones that are highly distinctive in their "natural" state (unmodified with added "flavors" that are used, for instance, with Earl Gray, Jasmine, or Lapsang Souchong) are somewhat rare to my untutored tongue.
Pu-erh is definitely distinctive. One of the great teas of Yunnan province, China, the pu-erh I've been drinking has a musty and mineral-y taste, and it's sometimes almost brine-y (my youngest daughter described it as "fishy," and I think she was reacting to the tea's oceanic overtones, which I think of as usually more characteristic of greens than of the darker teas).
The color of pu-erh is also distinctive. I drink my tea from a glass cup so that I can admire the color of the liquor, and this tea has a gorgeous reddish-brown, deep Burnt Siena-ish cast. On appearance alone, you can't mistake it for any other tea.
I drink a 20 year old pu-erh, but I've tried the 30 year, and they're both fine. I haven't developed the palate to distinguish the effects of different periods of aging (it's much less overt with tea than with, say, Bordeaux) , and discerning the difference between 5, 20,30 and 74 year old pu-erh is complicated by the fact that pu-erhs are frequently "blends," which adds another level of complexity into the tasting experience.
All teas are alleged to have medicinal value, but pu-erh is frequently singled out as good for the "health" (particularly as a digestive, and taking tea after meals is how my tea guru, Bill Holland, suggests one should drink tea with dinner, though pu-erh is also renown for its grease-cutting attributes, which might also make it a good accompaniment for a ham slice or, perhaps, a Napoleon).
Anyhow, thanks for the heads-up on Aion. Elsewhere on the forum, we've discussed the tendency of restaurants (even those serving high tea) NOT to bring tea to a full boil before infusion; I'm sure Aion does so, and I think it's really cool that they encourage multiple infusions and even give you the excess leaves and tea to go. Sounds like my kind of place.
Hammond
"Don't you ever underestimate the power of a female." Bootsy Collins