Expert advice on realtime Instant messaging in rails 3 ?

Are there any decent example apps for an ruby on rails 3 instant Messenger app based on any of the publish-subscribe messaging systems out there? ( Cram, Faye, Juggernaut )

I want to build a private 1-1 chat system based on these techniques but having a hard time finding anything decent examples, tutorials information to learn how to do this, let alone, choose between faye, cram, or juggernaut

Have looked at Faye, had some problems getting it up and running,

tried some cram samples from github, decent got some web chat apps running but none was IM or had feature to implement private 1-1 chats.

What are my rails options for building a 1-1 I’m chat?