Yeah I've been looking at this recently. I like autowire's ability to create typesafe APIs shared across the client and server. Very promising, but not simple to set up...
You don't need Autowite for that. That's pretty much basic functionality of Scala.js.
Really? From reading that guide I thought that Autowire made it easier by automatically doing the serialisation/deserialisation. How does stock scala.js do that?
Extra downside is code bloat. Scala.js on its own just maybe but combined with another major framework - forget it.
The amount of code bloat is offset by optimizing a medium-sized picture.