Mix together sour cream, goat cheese, vinegar, oil and dry mustard in a large bowl.
Bring a large pot of salted water to a boil. Add potatoes, and boil for 15-20 minutes, or until the tip of a sharp knife can pierce a piece of potato easily. Drain, and add to dressing in bowl. Toss well to mix, smashing the potatoes slightly as you do. Let cool to room temperature.
Mix in bacon and chives, and season with sea salt (or truffle salt, for something special).