I realize it's not a pure-Rust UI, but building with Tauri has been a joy. I recently built a GUI for one of my side projects and being able to use standard Typescript client-side development approaches, with a locked-down IPC, was surprisingly smooth. Love the "Wails-style" approach to a smaller release size than Electron as well.

It's nice to be able to use existing design systems and components, and to be able to validate in a web browser in quicker build loops before doing the full Tauri builds. I still manually QA across platforms pretty aggressively but Tauri's "cross-platform from day one" really isn't much of a stretch. The project if curious: https://github.com/zecrocks/zkv