For those already actively using GMail, Google Calendar and other Google services (including Search), the fact that the Plus Bar on top allows you to share link

For those already actively using GMail, Google Calendar and other Google services (including Search), the fact that the Plus Bar on top allows you to share links and keep notified across the web is a very big difference over Facebook. In that sense, already I see it having a better staying power than Facebook. Also, anecdotally, I am rarely logged in to Facebook constantly because it serves me no useful "productive" purpose. I catch up with friends and family only when I'm done working. With Google+ it is going to be that much harder because I'm always logged in to check mails and organize my calendar.