Pat wrote:
It is better to brew tea in a pot partly because there is more room for
the leaves/bags to circulate in the water.

I've been watching my tea brew for a while, and I don't think this
makes much difference once you get to a certain volume for the tea to
rest in; that being enough for it to unfurl without being compressed.
It pretty much just sits on the bottom of the pot after the initial
swirling stops (and it stops pretty quickly).

Maybe putting it in an infuser with holes on the bottom would result in
more circulation.

But I think it is mostly
because the teapot is covered and mugs usually are not. If you have to
make your tea in a mug, try covering the mug while the tea steeps.
This helps the water maintain the proper temperature and makes a huge
difference to the taste of the tea. I have a coaster at work that I
use to cover my mug while my tea brews; I get much better results this
way. Also, it helps to preheat your mug with some hot water
beforehand.

When I brew in a mug, I usually fill the mug with water and nuke it,
then add a T-sac. So the mug is plenty hot, often superheated. I
don't worry about covers. Not that cold around here...

--Blair