[easel]

There's a list of sites using scala.js on the website that evolves quite regularly. The scalajs-spa-tutorial at https://github.com/ochrons/scalajs-spa-tutorial is probably the best place to see a full stack app that you can poke and prod at. It's been through a few iterations by now and represents a number of best practices

The biggest benefit is probably having a solid type system that's isomorphic. Large, complex responses and post bodies can be seamlessly passed around with full IDE support and refactoring. Beyond that, it's scala.