What exactly does it mean to treat G+ like G+? I don't believe that there is a definitive way in which to use G+. Perhaps you can say that some people treat G+ like FB because of the type of posts that they share. However, that could also be related to the type of personality for the individual. Talking about where you are going, what you did and what you eat for the day may be associated with FB updates, but I can also tell you that that type of post is in my stream on G+ as well.
I often share similar or the same items on FB and G+, with slight tweaks due to limitations of both places. I don't discuss too much about my personal life on G+, which I never did on FB either. I'm more about sharing my musical and pop culture interests. Probably one of the better things about G+ is that it lends itself to longer posts, which I enjoy.
I don't know what the magic number is for me to follow, but I can only absorb so much information from my stream and interact with only a limited portion. I have interacted with a lot of great people on G+ and wish to continue growing in my experience here. The way I use this network may not be how others use it, but it works for me.