The prince edward is a great example of the power of bitters to completely change the character of a drink. The pdt cocktail book tells us that the original recipe had no bitters, making it a sort of wet rusty nail. The addition of a couple good shakes of orange bitters transforms the drink, sharpening the edges of what was otherwise a plain scotch cocktail. For maximum flavor, we like to use a combo of complex, spicy regans orange bitters no. 6 and the comparatively simpler and sweeter fees orange bitters.