On the nature of caffeination

I've been having a daily iced coffee for about a month now, and I'm learning a few things about the comparative levels of caffeine. I'd always thought that a cup of tea was about equivalent to a cup of coffee, but it ain't necessarily so--even if it's Yorkshire Death Tea.

Even when I was having a one-man pot of tea each morning, I never had much of the purported appetite-suppression effect, but with this shit, whoop! there it is. I've been known to completely miss my elevenses if I finish the mug early. And twitchy, oh my yes, twitchy. Not joy juice hyper-twitch, but...*twitch*

I'm a little dubious about the healthiness here. I don't imagine one cup a day is going to explode me, but.