There's still some verbosity. I would kill for C# like properties for mutable data classes (JPA entities). I also really like Kotlin/Scala style apply functions

There's still some verbosity. I would kill for C# like properties for mutable data classes (JPA entities). I also really like Kotlin/Scala style apply functions for interfaces and Kotlin's delegates for making easy decorators, but none of these have ever convinced me to leave Java behind. The only languages that have come close are C# or D because of their lower level capabilities.