Personally, I haven't been using G+ much. I believe that I was wrong.
The interface felt right. It's really brilliant. But something isn't clicking. Of course, they have a huge user base, so there is a real possibility to turn things around.
I think it's too early to tell. They're really shoving it down our throats with deep integration and social search returns. They're trying so hard to brute force it, and I'm not sure that they won't eventually succeed. Chances are they won't, but I'm just not convinced that we can call it over yet. I think this is going to play out over at least two more years before we'll know if it's gonna stick around in any sort of meaningful way.
The problem for google is that people's parents and grandparents are on Facebook. I mean, when they've penetrated that deep demographically, how are you going to yank them out into a new platform? Early adopters can only do so much. I think the most likely scenario for G+ (if it survives) is that it becomes a different social network alongside Facebook, LinkedIn, etc that serves a niche community.
I honestly believe that many people here are switching to FB because of The Social Network.
By the time they opened up, it was too late; they lost their momentum, and everyone else lost interest. Also, "Google+" is a stupid and clumsy name.
I don't need a replacement for facebook, because I hate facebook. Google+ does everything I want perfectly.
http://i.imgur.com/5ocCv.png Clicking on an item brings up comments, and lets you add your own, like this: http://i.imgur.com/mhAfy.png It doesn't have the power of threaded comments, but neither do FB or twitter. It is, however, easy to use and pleasant looking.