I like the Blacks, they are like a more potent and stronger (medium bodied) CAO Gold. Dont quote me since i haven't had one in a bit but thats what i rememeber. Ever had one Boom?
the only CAO's i've had are the Brazilia and the Italia, i've been looking to find some of the others but at the moment don't have the cash to spend, hopefully sometime in the near future

my "first to try" list goes like this...
-Black
-Criollo
-Gold / Gold Maduro
-Mx2
Cx2

if you know of a decent sampler that has some of these let me know