That is quite interesting!
I recently quit coffee, though not caffeine altogether. I just substituted about one liter of coffee per day with about one liter of green tea, which - at least the kind I am drinking - has way less caffeine. (And it tastes soooooo good! The coffee I used to drink tasted like industrial sewage in comparison!)
Before, when my alarm clock went off in the morning, I used to roll straigt out of bed into the kitchen and turn on my coffee maker before even getting dressed. Now, I make myself a pot of tea, when I arrive at work. I am still groggy when I get up in the morning, but less so, and it clears up pretty much by itself before I leave for work.
I remember the mid-afternoon crash rather well. ;-) I still get tired in the afternoon, but much less so than before.
I am not sure I want to quit caffeine completely (and besides, I really love the taste of green tea), but I find this post encouraging, if I ever wanted to try.
