I do it all the time. G+ is like having a blog, twitter and facebook all in the same place, so I can post articles, work-related things, and deeply retarded stuffs only intended to my friends all in the same place instead of having to manage multiple networks. I just need to select the right groups when posting and voila!
I can't count the number of bitching posts about the complexity of circles. But they are as complex as you make them.
You can tweet and blog (full-public post), send restricted messages (circles), or even private messages (single user).
I think the more interesting question would be "how many circles do you actively use"? I went circle-crazy and categorized a ton of people, but really only use "Friends", "Acquaintances", and two other circles -- both of which neatly translate to real circles of friends.
