From the looks of it, the author of these slides has written very little Scala. Take slide #7, for example, where he writes def bar() = { "1" } when def bar = "1" is perfectly sufficient. Ironically, I may very well be pointing out the bad parts of scala (i.e. that () is simply a convention for indicating Unit or side-effecting functions, but its just convention and not enforced by the type system in any way). Notwithstanding that, I don't think someone who has written very little Scala is in a great position to offer a reasonable critique.

This is a longer discussion, but in the very first slide he points to the object-orientation as a plus. In my opinion, he's already wrong. "There is no such thing as Object-Oriented programming." See: http://blog.higher-order.com/blog/2008/12/04/no-such-thing/