I've been on since the beginning, and I think it is becoming more mechanical. The only traffic is from people pushing things out. Some people get links from every cheap science article there is, and push them out. Others push out rote political viewpoints.
I've done my very best pouring some love into it, but I think it's on parched ground. The only thing was the hangout, but with only 10 people, the good ones fill out quick, and I feel bad that I'm keeping others out.
Photographers push out their pictures, some of which are very nice, but still photos only go so far. I don't know what I really wanted out of this, perhaps I wouldn't like anything (Hate Facebook!), but I don't see it moving into anything but a great place for pushing ads.
The blog satisfies me in the sense that it is a big soapbox where I can shout out and not care if anybody hears. I don't care that nobody every interacts. On g+ you expect people to interact, and nobody does.