We've tried several collaboration systems in the past, but having Google + integrated in the Gmail toolbar is a major usability advantage. However we're going to have create some specific "best practices" and guidelines before turning it on for everyone, because they will have the ability to have people in their circles who are not from our domain. I enabled it within minutes of getting notice from Google that it was available. We're turning it on for a few who have already been using Google+ personal accounts so that we can feel out some of the pros and cons and address them before we roll it out to everyone.