I don't really drink tea, but I will say it's better than coffee. Caffeine is just too addictive, and should be used sparingly.
I know some people who used to be, like me, able to weather 72 hours of being awake with near-to-full functionality before needing to go to sleep. Then, since they started drinking coffee in the morning, they're always tired and angry when they don't get their fix.
Personally, caffeine doesn't really affect me much anyway. I must have a lead stomach, because alcohol and oral drugs don't really do much for me. This is probably the only reason I didn't give in and transform into a rabid coffee drinker years ago.