I think you missed the "and for Facebook, etc" portion of "tablets are quicker".
For most forms of consumption, a reasonably-powered tablet is a more convenient device for many of us, and using an operating system (Android, iOS, etc) that is designed for instant-on operation and is optimized for consumption on-the-go, a tablet is the way to go.
But I don't like typing a lot into it, so for content CREATION, it's a whole different ballgame. I want a large screen, a real keyboard, and lost of space to store my content.
I read Google+ on my phone and/or tablet more often than my computer. I even type short posts on it. When I want to type something like this post, I go to my computer.