I have also joined Google + but found is average so far....in terms of traffic and social networking as well.
i do believe google+ is really good social media network and it has a +1 page which can drive lot of traffic.
That is the nice step to join to Google+ it is the one of the best social networking site like Facebook.
Yes Obviously Google + is the best site and it would beat Facebook very soon. and i think it can be very beneficial for SEO purpose too ..
Great that you've joined it... that's a really cool service and finally it become easy to join without an invitations....