In a large pot, combine the potatoes with 1 teaspoon of salt and enough water to cover by 1-inch. Bring to a boil. Lower the heat and simmer until the potatoes are fork tender, 10 to 12 minutes. Drain and let cool slightly.
In a bowl, whisk together the mayonnaise, sour cream, buttermilk, mustard and pickle juice. Add the garlic, dill, remaining 1/2 teaspoon of salt, pepper, and cayenne, and whisk to combine. Place the potatoes in a large bowl and add the dressing, tossing to coat evenly. Add the eggs, pickles, onions and toss to combine. Adjust seasoning, to taste.
Refrigerate until cool, 2 to 3 hours, before serving.
Yield: 6 to 8 servings