Another thing to think about is OAuth. If you if you lose an account at Google or Facebook that you've used to sign into another site, you lose them too.
Will not using G OAuth and probably delete all photos from my Picasa, now that they were automatically moved over to G+.
You never know what the automatic image scanner may think it has found in those photos that violates some G+ rules. I don't want to lose all my data in my G account, only because an automated scanner thinks my friend's face was a bare female breast.
