I use Preact. I like it a lot. Started with pure ES6, Preact, and htm templates - no transpilation step! As the project got bigger I migrated to Typescript and start using it's built-in JSX compiler. Was a pretty easy step. My only package dependencies for a long time were preact and preact-router. Recently moved to webpack to support proper packaging of node modules when I moved from REST to GraphQL. But no babel, and it's been really nice to slowly increment the build complexity only when it's been needed.