I have give up coffee, but not caffine, for lent this year. I am a coffee drinker, I love drinking it at work sitting at my desk, when I'm driving, when I wake up, etc. I drink it black, nothing fancy.
I have noticed that since I stopped I am drinking a diet soda every other day, and black tea in the mornings, but my caffine intake is nowhere near where it was when on coffee. I dont feel any better or worse, but now that I think of it I have not felt as sluggish mid afternoon like usual.
I am very much looking forward to grabbing a cup of Dunkin on Easter Sunday when my quit is up, I just enjoy coffee.
Good luck with the energy drinks, I never really got into those, too much sugar for me.