I quite enjoyed it! There's an intellij plugin that converts html to kotlin xhtml which gives you pretty much all the advantages you get with html syntax based techbologies like jsx. The tooling support makes abstraction and refactoring a joy. Readability is fine, but large templates and a lot of styling will be as demanding as in pure html. I think it's the best solution for any language that doesn't want to include html syntax. There are even proposals for an equivalent for typescript for tsx replacement, because people realize how much nicer it is :)
But this is only Part of the story, because you need to think about whether you use it from your backend (spring, ktor or whatever) or from the frontend. If you want pure frontend, then it would probably be the kotlin js react stack, which i was also very satisfied with, but it has some rough edges.
For personal projects, i recommend it every time. For production use, xhtml is fine, but the react kotlin stack needs some things fulfilled at your work :)