16 oz is not that much, although cold brew is a little stronger. I used to consume a about gram of caffeine a day but withdrawal for me was a light headache and slightly lower energy for a day (I went no caffeine for a little while to reduce tolerance). I did notice my energy improve without it, however I am sometimes not able to get enough sleep and it is good for leveling out energy in those cases. I generally try to have low doses and occasional strategic bursts when necessary. Also if you are worried about sleep you can do the math using the half life of caffeine (5 hours avg.) to figure out how much you are on when you go to bed. Sorry if incoherent, I have been busy this week and not getting much sleep.