^
Not too sweet, the lime is tart enough to balance out the simple syrup and the liqueurs, and you can always adjust it to taste. The easiest way is to use a straw with your finger over one end to pull a small taste out of the shaker before you pour; if it's too sweet, add more lime, too sour, add more simple syrup or Maraschino, more rum if it tastes weak, etc. You'll see bartenders in serious cocktail bars do this, it's like a chef checking the salt at the last minute before sending out a dish.
If you really don't like sweet drinks, you can make a Hemingway Daiquiri, also known as a Papa doble:
3 oz light rum
1 1/2 oz fresh lime juice
1 1/2 oz fresh grapefruit juice
1 oz Maraschino liqueur
enough crushed ice to fill a 12 oz glass
Put it all in the blender and blitz it until it's smooth.
These things go down easy, but pack a lot of liquor, so unless you've got the tolerance of Old Papa, who'd down a dozen or more of these things at a sitting, take it easy.
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Your boos mean nothing, I've seen what makes you cheer.
- Rick Sanchez