The clue to both these responses is in the name – Google+. With more than 80% of online searches going through Google now, it makes sense on every level to take advantage of their very own networking tool.
For me, it always boils down to being found by the Google-bots. All the content you put up on Google+ counts toward your overall SEO ranking, because Google indexes Google+ content in the same way it does web pages. This means that when you post to Google+, your content is searchable, it ends up higher in search results, and it appears in search results for a longer period of time than if you posted that same content to another social platform, like Facebook or Twitter.
Google+ may be taking off at a shallower angle than say Facebook or Twitter, but with every new enhancement Google brings it’s going to get bigger, better and more important in the world of SEO and online searches.
Establish yourself there now, it’s the wise decision.