I'm sorry to be getting back to this so late. Ours turned out pretty good. Not phenomenal, but pretty good. When we brewed it and when we racked it, it was inky, inky black (from all the suspended cocoa powder, I think). But by the time it was done, we wished we'd put in a second pound of cocoa powder. The chocolate notes ended up being very faint compared to the cherries (which we pureed in a sanitized blender and added to the secondary--it didn't cause any problem at racking, though a few floaters made it into bottles). One of my partners said he thought there was a cough-syrupy taste, but I disagree.
The best thing about it, really, wasn't our doing. The mouthfeel was really great, and I think that was from the lactose in the milk stout recipe.