Funny you mention that. I bartended over the weekend and probably make 20 of those. That, and the Communist were by far my most popular drinks.
I did some playing around with the Derby and found that the Napoleon works well in it, in fact that's the only drink I really prefer it in so far. For bourbon, most people preferred Blanton's, compared to the other things I had on hand. Anyways, I was surprised it was so popular, in fact a few people asked to taste the ingredients seperately, and they said that the Cocchi and PeM was the subtle flavor that they really liked in the drink.