I've actually been looking into it a bit more. The main thing I really like about it, as sort of mentioned before, is being able to separate What you share and to who...but I wasn't sure about posts.
I figured out today (using the term "wall" so its easier to understand) you have unlimited walls. Unlike facebook that has 1 wall that everyone that makes a post that is your friend, you will see...... G+ has a wall for each "circle" you have. So, using an example: If I wanted to post something about atheism and prefered my "christian" friends not to see it, I just have to make a circle and add friends that are not easily offended. You can name the circle what ever you want, so it's easy to remember what type of people are able to see the wall in that circle. Another example. If I had added a bunch of co-workers but hated my job.....I could have a Co-Worker Circle that I only post good things about my work, and a Non-Coworker circle that all I did was talk shit about my work. Neither circle would be able to see the other circles "wall". However, You can place 1 person in more then 1 circle. So if I had someone I didn't care if they saw both, I would just add them to both circles. Also, the people in what ever circle you put them in, have no access to see what circle they are in on your list.....nor how many. They will just see your posts on their "wall" under what ever circle they have you in.
Same thing with family. If you have people in your family that are conservative or older and don't appreciate more adult joking around, just don't post on their circles wall....and they won't see it. Or if you have friends that post stupid shit all the time, make a "stupid friend" circle and you only have to view their wall when you want to
Same thing with people who constantly post youtube music videos all over your facebook wall.....give them their own wall and you can ignore it easier.
And to clear it up, the "wall" in G+ is called the "stream".