Oh wow, I feel like a kid alongside the grown-ups! Far too sour for me. The lemon and orange just blow out the Bourbon and the rum for the most part, with the dry spirit forward hit of the Bourbon in the end. The rum is barely there, with the Triple Sec just not even existent. I would love to try this with a sweeter orange liqueur (maybe my Curacao adjunct).
Re-visited this cocktail and changed a few things. Went with Appleton Estates 12 yr rum ( since the 12 is aged in ex-Bourbon barrels), used a local Bourbon that was very oak forward (Fiddler Georgia Heartwood) and used Grand Marnier as recommended by John. Definitely became more complex. The oakiness of the bourbon and rum really played well off each other, the citrus was also prominent and the slight amount of simple syrup really balanced it. Really enjoyed the new combination.
Delightful cocktail. Dry with some slight sweetness from the Cointreau and orange juice. Bourbon forward at the beginning and the rum at the end. May try it again using Grand Marnier in place of Cointreau to add a little hint of Cognac.
So the next night we made this with Grand Marnier instead of the Cointreau. It was a lot drier, but the added hint of cognac was great. If you want to use Grand Marnier, I would suggest a little sugar syrup if you want it sweeter. It was perfect as we like dry cocktails.
The main review describes it perfectly. A very dry, citrus sour cocktail that ends with the rum ( El Dorado 8 yr) really coming through at the end. A really nice sour.