Google + is the new social kid on the block, with limited Beta every one is trying to find a way in.
What I think Google + does better than Facebook is control the way you post your content. The ability to send your posts to selected people/circles is a great idea. I have not used Facebook a tone because I find it frustrating to use, The layout is not intuitive at all.
At the moment Google + is Ad free ( I assume this will change in time ) but the layout matches that of Google Search, and G-Mail.
I would invest the time to share links, images, and videos on Google plus over Facebook. I also consider Google + to be a bit more personal as in it’s not full of other people’s junk. Your profile page looks more or less like a Tumbler blog.
So far so good.
With Google having the +1 button in the search results it is giving a lot of power to users to promote the websites they like. This will most definitely effect SEO as I would think organic recommendations will be valued higher than text-based keywords, and thus adding value and relevance to Advertising. Google will know more about you and in turn deliver more content you “like”, much like Facebook.