This question is tied to much deliberation.
Clearly, caffeine effects people differently. The type of caffeine you consume also makes a difference.
The clearest best short and long term advice I feel I have heard is: Anything chemical (natural or man made) that gives you an energy boost, does so by using your body's stored resources. To use these products depletes these resources. If you use too much, it can seriously affect your health. Giving yourself time to replenish and sleep are vital for long term health.
Now that you have asked the question, I think the time has come for you to do some research and find the answers for yourself.