It seems that typed actor support it somewhat incomplete. Once you wanted to use typed actors with routers and resizing, there was no documentation. There were some mailing lists posts with suggestions that don't work. I don't know if anything changed in the meanwhile, but this blog post suggests that it's still not well-supported:

http://blog.codacy.com/2014/01/29/typed-actors-with-routing/

One thing that I dislike about the Akka implementation of actors is that they can't block, because this would block a thread in the thread pool. Quasar's implementation of actors allow you to block on e.g. I/O, because Quasar can preempt fibers that are parked. This makes Quasar's actor framework much more powerful and more Erlang-like.

Under Scala 2.10 there were bugs in the reflection system that made those almost unusable; is that now all fixed?