I installed Google+ fairly early. Before the public release. I have one friend who posts several times a week. Maybe four other friends who post once every week or two. Lots of people who follow me, but since I don't post anything public- I don't see the point. I can read their posts, but they don't really interest me. None of my family or close friends have adopted it. The interface seems awkward and boring. It is not visually pleasing.
Did you watch F8? I was entranced. I wasn't as annoyed by the Ticker as most- I gave it a chance, and now really like it. I appreciate the little not-so-important comments being removed from my news feed. I installed Timeline as soon as I discovered that could be done ahead of time and have worked the last two weekends adding content from milestone events in the years past. When I look at my timeline, or those of my few friends that have taken the time to install it ahead of time, I see a rich, colorful, interesting documentation of what my friends want to say is important in their lives. I don't know about Open Graph- I'll have to see what it is like when it goes live and I am able to install some of the apps. It looks very interesting, though.
I have _lots_ of close friends, acquaintances, family, coworkers who actively participate on Facebook, most daily, lots constantly! Compared to that, Google+ is just so barren and sterile.