I was a heavy coffee drinker for years from my teen and then, some years ago, I switched to tea.
After that, I used to drink 3 tea a day but gave it up to the advice from food sensitivity clinic a couple of years ago. The difference is unbelievable in only few days after giving up the tea! The effects were heart skipping, very tired, headaches lasted a day or two and the time ticked very slowly thus making a day feels like 1 and half day! Also slept like a log at nights and hard to get out of bed in the mornings!
Glad to say that the effects didn't last long but needless to say, I gave up tea...only drink a couple of coffee on weekends and also accept tea when visiting friends etc.
I now drink barley regularly, I got it from the health shop.
From the experience, I believe that both tea and coffee have the same amount of caffeine but why drink tea when you have a nicer coffee?