Really very good. Having not made a rum old fashioned before I was drawn to the idea of blending rums to achieve a complete drink. I have made this as specced, yet it works very well with a wide range of rums if you play with the ratios: I really didn't think Pussers naval with Barbancourt 8* had any right to work. The Falernum (or equivalent) really is critical to success I think, along with the right garnish.