I decided not to. I was talking with my close friends, the ones I have the message thread with on FB, and we tried (for 30 minutes) Google Plus and adding each other into a private circle of our own and sharing content and discussions there, but G+ is just shitty and has nothing that's identical to FB Messenger and even sharing content with a small group of people is a chore, since it's tough to navigate between feeds of who you follow and who are your actual friends (IGN vs. Joe Smiht, the best friend).
Fuck Google Plus.