Google has released Hangouts 2 which gives you additional benefits of sending and receiving SMS right from your hangout application.
Hence, the over all experience of application is much more smoother and definitely richer.
You can download the file from here
The new Hangout first got released as Version 2.0.12 which was having some issues with Video chats but the current version i.e Version 2.0.122 is expected to resolve that.
Currently the APK is only for Nexus 5 in the Android Market but it ain't gonna stop you from getting it ;)
Lemme know about your experience with this version.