Do you think such a configuration could outrun the Vert.x configuration they've posted? I'm not challenging you, I'm just genuinely curious! Because if Play+Akka can outrun Vert.x, then it would be an interesting game altogether...
I think Play, with well-written asynchronous code, could approach the Netty/Vert.x speed. In other words, I'd be willing to trade the ease-of-use of Play for the slight speed impairment vs. writing directly to Netty/Vert.x/etc.