Both Netty and Play use Jackson though one the Netty version uses a single ObjectMapper and the Play version uses a new ObjectNode per request (created through Play's Json library).
I read the performance analysis comparing it to Go, Erlang etc. Has any comparison been made with Akka (http://akka.io)? How much would this extra efficiency matter when the communicating processes are on different machines? Since speed in communicating between local processes is important to you guys, I am assuming that the actor model is then used for all local and remote communication?