The essential difference between Facebook and Google +, for me, is this: I am interested in what you post on Facebook because it’s you. We are (real) friends, family members or church members together. We have a real world connection that is typically not interest driven. I’m interested in you as a person. On Google Plus, I’m interested in what you post because it’s intrinsically interesting; it’s well said and an interesting topic to me. I typically don’t have real world relationships with folks I follow on Google +.
So, at least for me, there is no Facebook vs Google +. I’m happy to have two different places for these very different streams. I’ve seen various posts saying similar things but this really gained clarity for me when I add a circle someone had shared without sufficiently vetting it first. I’ve since “unfollowed” most from that circle. The quality of “the stream” is much more important that quantity. I scan through Facebook posts and pause briefly when my interest is piqued. I browse carefully through Google + post. This partly due to comments; they are often at least as interesting as the original post. This is inordinately rare on the web, especially comments on a blog/web page. Those a typically glib, inarticulate and brief. Not so with G+ users.
What’s your experience? Mileage may differ but I’m guessing you’re doing very different things on each platform.