Yes, but that's still a significant amount of friction for something as important as understanding what your social context is. And how many people are really going to understand that that distinction even exists?
I think the real problem is that there's no easy mental model for the way information flows through the system. That's what metaphors are for. A "Circle" is not a metaphor. It's just a brand.
Sorry, I thought you were just asking is it possible to see the context. I wasn't looking to defend the product. That said, though...
I don't think Circles intends to aid in setting social context for other people. It's intended to help the sharer set context for who will see their content. Google is betting that people will share more information if they can limit it to the right groups of people.
As a commenter on this content, I don't get to reset the context or modify it. I can either trust the initial poster's choice or I can dig in further. The mental model is pretty simple: I trust the poster or I take a look around the room and see who else is there. I think when people do dig in further, they will either see a small group of people that they recognize or a large group of people which will set them in "public" context mode for commenting.
The people that don't notice are the same ones spamming their friends with FarmVille invites and there's limited controls for blocking them without disavowing them entirely within Facebook. They're the people that post drunk pics to Facebook in "Everyone" albums without any consideration.
So what if they use + the same way. Ignore them, move them to a quieter circle. And for their benefit, it defaults to a more protective privacy setting than Facebook, especially for pictures.
I definitely agree that Circles are better. I don't think they're as good as they could be. I don't think it's that clear for people, even those that are outside the group you cite, where exactly their comments are going. It's discoverable, but it's certainly not immediately obvious. I think privacy usability is really important, you want to make that stuff as easy and intuitive as possible.
I think the real problem is that there's no easy mental model for the way information flows through the system. That's what metaphors are for. A "Circle" is not a metaphor. It's just a brand.