An interesting drink, one that I would probably put into the "after dinner" category. A little on the sweet side, with what I would describe as having a somewhat "thick" feel in the mouth--but not unpleasant by any means. For the rye, I used top-shelf 6 year-old Sazerac rye. I agree with one person who thought that the person who posted this cocktail should have specified the bitters to be used. I used black walnut as suggested by another person, but I was not entirely satisfied with the outcome. While it was not a bad choice for a bitters with this cocktail, I think there's probably a better choice. I just don't know what it is!
Regardless, the basic drink is a good one, however I would not use an over-proof rye such as Rittenhouse because such ryes can overwhelm the other ingredients. Some solid ryes in the 80 to 95 proof range to consider are Wild Turkey Rye (81 proof), Michter's (90 proof), and Bulleit Small Batch rye (95proof). Now to search for a bitters that will complement the flavors in this otherwise great cocktail!