Did you know that when you register a domain you are required to provide your address and phone number for a public database with no access controls? That's more personally identifiable information (PII) than I've provided any of the "social" networks. I get a couple of hundred spam a day directed at me through my Registrant Contact.
The content I'm publishing on Google+ is mostly also published on my web site, but I get a much wider audience using Google+ and Twitter than I have through my site. There is far better interaction of both of these services (people who respond to content I've published, or share it with others). So far, Twitter is still the most successful medium I have used to increase reach.
From everything I've observed about company behaviour and public statements, as well as the way the services are constructed, I'm far more comfortable with Google+ than Facebook. FB has made a concerted effort to play to addictive behaviour in its product to increase "stickiness" (the amount of time people spend looking at it). Google is also climbing, but through the expansion of useful services rather than cheap tricks like the Facebook "ticker" and constantly forcing game updates in your face.
If you have your documents in Google Docs,
Google already have them. You don't need to sign up to Google+ with the same account you use for your docs. I don't. Only give the service information which you're happy to share anyway. I publish almost everything that I post on Google+ as public posts on my web site as well. Google already has this, as do Bing/Yahoo and anyone else with a web browser or a perl script.
As to Terry's point about many existing forums using older tech, I agree. I still regularly use Usenet and mailing lists as much as web forums or social networks. Where the social networks excel is in reach (the size of your audience, the ability for people to find your content, and the sharing of content) and the easy integration of modern content types like photos and videos. I find it much quicker and easier to post my
Vintage Computer Friday to Google+ than my own web site.
But again, do what suits you. I'm not trying to influence, just educate.