A favorite of mine; but my Lady finds it a bit too alcohol forward. I've substituted the different Elderflower Liqueurs, and tend to favor the St. Germaine. It's excellent; but the others produce a tasty cocktail, that's rewardingly pleasant. As an aside, I ran out of limes, and mixed one with .5 oz. of fresh squeezed lemon. Delightful. The cocktail seems to support a variety of tinkering, before becoming distasteful.