Having energy and focus without the need of an external substance, better quality sleep due to residue caffeine not in your body not allowing you to have full REM cycles and not over working your heart. How these points are getting lost in this conversation is beyond me.
Oh my, what's that, the first link? And subsequent links from different health authorities? Oh my, what a difficult google search that was... Seriously, don't be lazy. That's bad for your health too.
You didn't say what the upside is.