I really enjoy Google+. It honestly has become my defacto "social network" when I just want to peruse whats happening in the world. There is a video game that I have been following for the past few years that went live this weekend and the community on Google+ is head and sholders above what I have found in other places. The content (as a whole) has been more thought out and and as a percentage I have wanted to read more of it than other sources.
That being said I think "circles" caters to niche groups of people wanting to discuss a certain topic, will be interesting to see how another "post fencing" appartatus plays with circles.
I have never used facebook, twitter, etc., but I have increasingly found relevant content and discussion on g+ pages.
So much so that last week I attempted, unsuccessfully, to create a g+ account for rsync.net. You'd think that wouldn't be rocket science.
Then all of that "real name" bullshit that I tried to ignore last year came back to me. Google refuses to recognize the account, blah blah blah.
No, I am not giving them my personal information for these discussions, and furthermore, multiple different people will be using this account (it's a business account) so it's not appropriate to tie an identity to it anyway.
I think the use case you describe is that you create a Google account as yourself, along with each of your colleagues. Then you create a G+ Page and make them all administrators of it. You can act/post/etc. as the G+ page and not as yourself, e.g. https://plus.google.com/+TheCorcoranGroup
Not saying this is ideal or that you should like it, just that I think that's how you can do what you want to do.
I've been following GW2 on Facebook and the community is terrible. Never thought to check it on Google+. (I'm assuming GW2 is what you're referring to).
That being said I think "circles" caters to niche groups of people wanting to discuss a certain topic, will be interesting to see how another "post fencing" appartatus plays with circles.