Why it's worth it
Six bowls run from 0.75 to 8 quarts, from a restaurant-supply brand that builds to commercial food-safety standards. You get a small prep dish and a bowl big enough for a double batch of bread dough, and you give up non-slip bases and measurement marks.
Six bowls means you stop washing in the middle of a recipe. The set runs 0.75, 1.5, 3, 4, 5 and 8 quarts. That's a small dish for chopped garlic, a medium for dry ingredients, a big one for the batter, and spares. If you've ever rinsed the same bowl three times making one cake, the extra bowls are the real upgrade here, not the steel.
The 8-quart bowl is the one most sets don't include. Three-piece sets stop at 5 quarts, which is fine for a single loaf and tight for anything bigger. Eight quarts takes a double batch of bread dough, a party-sized salad you can toss without flinging lettuce across the counter, or a brine for a whole chicken. That's the reason to buy six bowls instead of three.
From our review of 8 stainless steel mixing bowl sets, by David Sinclair, Managing Editor