Very good drink, but for the second try we adjusted the recipe.
Found it a bit sweet for our tastes so we forgot the sugar syrup and substituted 1/2 the amount of Giffards Pamplemouse liquor. Added a bit more grapefruit flavour.
Used a Barbados gold as it has no adulterated sugar.
Added a few drops of Difford's Daiquiri Bitters.
Served over ice and it was PERFECT for our tastes.
Spirit forward and not too sweet.