Cut potatoes into bite-sized pieces. (I cut mine into quarters then cut each quarter into thirds.) Place in a pot of water and bring to a boil and cook until potatoes are fork tender (about 10 minutes).
Drain potatoes, season with sea salt, black pepper, and garlic powder, then allow to cool. (To expedite cooling, I spread potatoes out on a baking sheet and stick in the freezer while completing next steps.)
Simultaneously, boil eggs in a separate pot. Drain, cool, peel, and chop eggs to desired consistency. (To expedite cooling of eggs, add ice water to the pan and set aside.)
Chop celery, pickles, and dice onions. Set aside.
Mix mustard, mayo, sugar, and balsamic vinaigrette dressing in a small bowl until uniform. Set aside.
Add all ingredients to a large bowl and toss until incorporated and well coated with mustard combination.
Chill until reader to serve. Best eaten cold.