Tea for two and....
Whirls,
You are correct about the amount of caffeine per cup of tea vs coffee. However, tea also has a lot of tanin, which can in some affect the metabolism of the caffeine. And as for the diet coke. Is that diet coke minus just the sugar (which is replaced by phenylalinine, or Nutrasweet as it is commercially known) or minus the caffeine too!
A predicament either way!!!
TK