Today Bun v1.0.3 has been released. But it's still not ready for production in most cases. Eg. cluster module is not implemented yet.
I also wrote a blog post about Bun (the pros and cons): https://blog.melroy.org/2023/bun-v1.0/
Whether you will try to migrate to Bun it up to you, just know that Bun isn't a fully drop-in replacement of NodeJS. Maybe it will never be? Just like Deno is also not a replacement of Node.