My experiences of G+ were very different than some I've seen described. So different that I had to wonder how these people were using it.
I had a handful of communities and a large list of scientists, science writers, futurists, sci-fi authors, tech commentators, space industry types, Elite Dangerous CMDRs, skeptics and a handful of friends in my circles. I never once came across the 'deluge of porn bots' or the hate speech I've seen some people talk about. In there years I used it I could count on the fingers of one hand the number of times a post like that made it into my stream. They were reposted, but always came with a commentary about how crazy/irrational/wtf the post was.
Crazy commenters were also a rarity. Except on the aforementioned reposts of crazy. But you expect that there.
The other common claim I've heard was that G+ was a wasteland. Tumbleweeds and all. This was definitely not my experience.
Compared to my 3 forays into Facebook it was bliss. Intelligent commentary, engaging well thought out responses was the order of the day.
For reference, the Facebook accounts were due to needing to be there for other reasons and the longest lived one was 3 months. All were shut down due to the volume of irrational commentators that couldn't talk themselves out of a false dichotomy if it was presented to them as such.
From a comment on Pluspora.