From my - some years, but rather limited - experience with Scala (compared to a decade of Java), the largest point for Scala is how it works with monads e.g. Option, eliminating a lot of "if" statements and making APIs much clearer. And I did not expect this to be the main difference to Java when I've started working with Scala some years ago, I thought it would be closures (which are a nice thing, I especially like the _ syntax).
Don't you have to have closures to make monads work in practice? (I only really have experience with monads in Haskell, and something like (a >>= \x -> b >>= \y -> g x y) is a very basic thing to do with monads, there.)
