Facebook i've resigned is primarily for family and close friends. I'll never convince them to change over so I've stop trying. It is what it is. I did however purge a ton of contacts and widdled it down to just my close friends and family. Primarily a place to share pics of the kids for relatives that want to keep tabs. Also - my friends that won't jump ship - its my only form of communication via the internet - who uses email anymore?
Twitter i still use - but i've noticed now - i'm not addicted to it as i was last year. As Twitter has gotten more acceptable in my neck of the woods - i've found its become more spammy. Again - I've wiped out a lot of people i followed as most of them have learned how to use hashtags. So for the 'subjects' i'm interested i search via hashtag. Only the musing's of people i enjoy are now only on my follow. Keeps the timeline nice and tidy.
So Google Plus - is now my go to social app. Here's why - Google Plus does communities really really well. There seems to be a very positive vibe and a lot of cautious and carefully thought out posts. I think people are this way because they don't want this platform to be bogged down with mental diarrhea spilled out into their timelines.
The communities are also a great way to mine information. I view them as BBS Lite. Forums that allow you to post links and videos and engage in conversation like formats without trying.
Google Plus - the 'feel good' social media platform. Try it. Once you figure out what it does for 'you', you'll see where i'm coming from.