I had a taste of the 15 recently, it was at a bourbon bar in Newport, KY which John Lipman took me to (John writes up a historical American whiskey website well-known to some here). It was very good, with a distinct peppermint note.

About Tom's comment that many small barrels have a "green wood note", I would agree with this. Not sure why this is, it shows as a "pine sap" taste to my mind.