># Generally, on an average, 1 line of Scala = 10 lines of Java. That's less maintainable LOC (it can be argued otherwise, but just assume it's a good thing)

># Performance. Now this is where Scala really shines. Scala's base performance is almost near Java's in most real world scenarios.

Scala's great, but don't overhype it. I just finished re-writing a mid-sized (~30k LOC) API app from Java (Play 1) to Scala (Scalatra). In this case the code size was reduced to about 40% of the original, but we needed about 50% more CPU and 100% more RAM to get comparable performance.

It was still well worth it - aside from the reduction in the size of the code there are additional maintainability benefits from immutability and other nice aspects of idiomatic Scala.