I have about 500 Facebook friends, but only about two dozen in a family channel and another two dozen in a Close Friends channel. The bulk are in channels for work colleagues (big company), business contacts, and people I know who live abroad. Today, I wouldn't friend most of the business contacts, but that's ancient history.
I've lived in North America and my wife's family is Chinese so we are pretty widely spread. I have close relations in five different countries, but the majority are in Asia.
So, in an average Facebook session, I see posts from about 50 people, and I know almost all of them very well. I see a lot of baby and toddler pictures, with more to come ;-)
I have no relatives at all who use G+, and very few colleagues/business contacts who actually use it. Also, I don't see much new content there. I've usually seen it already via Twitter, Reddit, HN or RSS feeds.
I also use LinkedIn and Quora, and as a former /. and Digg user, I sometimes drop by those as well. They all have their niches. Unfortunately, it's hard to see anything that G+ does better than the rest, from my point of view.