I've been thinking about qat a lot these past few days, so I'll tap out of the Far mode discussion. Just this: my problem with coffee is that people are often given too much work, which they require coffee and similar stimulants to accomplish. (Witness: programmers' love for soda; project deadlines at university.) Qat doesn't seem to have that problem.

It does have another problem: if you don't want coffee, it's usually socially acceptable to drink another hot beverage (though if you don't want tea either you're kinda screwed), whereas qat lacks an alternative.