Did you know that Yerba Mate has caffeine too? Less than coffee though.
I love a big coffee in the morning and one in the afternoon. If I'm going to the gym after a long day at work, a little cup of coffee helps get the energy up! I don't mind using it as a stimulant, but I might want to switch to tea eventually. I'm so used to the caffeine though...
As far as addictions go, it's not a bad one. The worst effect for me is the tendency to buy coffee instead of bringing it to work in a thermos. Even cheap coffee- that adds up.