Another way to summarize might be to say, "If you discount the many examples of incorrect behaviour that paulp mentions, and you don't care about performance, and you are comfortable enough looking through the extremely deep collections hierarchy code to diagnose the reasons for these problems, then the standard scala collections library is almost as good as collection libraries available in other languages".

The AnyRefMap may be a good solution to many of my issues with the default map implementation once it is widely available. It won't help with the more general lack of cohesion in the library though.