Having seen how vibrant the discussion is using these features at Google, I have to disagree. In my experience, G+ is really well-suited for this, and it's way easier than editing a wiki, for example.
My problem with that datapoint? You work at Google. G+ is your (company's) product. I assume that you had a headstart using G+ (the basic thing) as well and I also assume that this thing is already heavily used.
I just don't think that this translates to other places.
(Forgive my ignorance and correct any mistake in the generalization hereafter):
A huge company with a number of global offices all over the world, full of internet savvy, always online, 'young' early adopters doesn't seem to be a good example for things that make sense in general.
Or in other words: I have trouble mapping your experience to any place I worked at so far, plus any customer I've been in contact with here in Europe (with a heavy focus on Germany).
Here's a post from another company that's been using it: http://tomcritchlow.com/private-google-plus-engagement . I understand that some people might be skeptical of G+ in the workplace. Some people were skeptical of Google Apps in the workplace, and that's fine. But G+ can be a really powerful tool for companies that want to use it.
One more anecdote: I have a friend whose company just moved from Lotus Notes to Google Apps, and they love Apps. I can easily see people in that company hopping on video calls or posting internally.
