Mark > The Mayans drank it cool with added water, and often with no sweetner, just herbs and spices.

You make it sound like everybody in MesoAmerca walked into their local 7-11 and bought themselves a bitter cup of the stuff.  Cocoa was a sacred brew and, although the average joe could get a sip of it on occasion, it was "primarily rulers, priests, decorated soldiers, and honored merchants [who] could [regularly] partake of this sacred brew." 

One other thing not yet mentioned.  Cocoa was in ancient times -- as it still is -- farmed.  I don't know how edible the aboriginal plant would have been.

Jim