User interface on Google+ Hangouts are more dynamic and attention grabbing because in the video chat window, the camera switches to the face of whomever is speaking at the time, versus being static through entire conversation.
But technical difficulties are inevitable. Someone’s bound to have a poor connection, and there will always be users who are unprepared for the experience. And since Google+ Hangouts are hosted by Google and not your own software, you’re out of luck if Google itself ever has technical problems while you’re chatting.