Cool thing about Xtend is that you can actually understand the Java it generates. So once you've used Xtend to generate the Java you can forget about Xtend if you want to. You are not "married" to it.

You can later take a Xtend-generated Java-method and start manually modifying it if needed.

I just wish Xtend had more support from others besides Eclipse. Also I hope it gets its Ant -support to a better shape, maybe it already is. It is simply a smarter simpler way to write Java. And you don't need to go Java 8 to benefit from "Lambdas".

Kotlin compiles to bytecode, Xtend transpiles to Java. Depends on situation which is better.

minaandrawos's question is really good. I don't know at which situations Xtend would make more sense than Kotlin or vice versa, but I would like to know if it compiles as slow as Scala.