For my vintage colored kettles, I very much appreciate the perfectly contoured design of the SnS which both protects the porcelain and maximizes 2-zone cooking space.
Essential? No, but I use one every time a colorful kettle comes out to play. I’m really looking forward to a reissue of the SnS LP to get my Aristocrat and Chief into rotation. But as much as I appreciate their 18” version in SS, it did not imitate the same perfect contoured fit to the bowl like the 22 and 26 versions.