>My question is:  can anyone tell me if they've been using green tea -- how
>much, and whether or not they've noticed any affect from the caffeine
>content?

I was completely off caffeine for about a year prior to going to Japan.
I was in Japan for about a year, during which time I drank green tea
every day, usually at breakfast and dinner (my host family served it).
When I cam back to America, I was noticeably and fairly strongly
addicted to caffeine, and had to go through a similar withdrawal
process to the first time I quit caffeine.

(I am presently off caffeine and have been for about 5 years.)

Most of the health benfits that I hear about relating to green tea have
to do with its value as an antioxidant.  However, there are many other
antioxidants that are paleo and caffeine free, and the paleo diet is high
in them.  So, if you're already eating paleo, there's a good chance that
adding green tea to your diet would be irrelevant, in terms of health
benefits. (*)

-Bruce
(*) my opinion.