Google+ was recently updated with an improved interface, but this article points out that Google+ still has a big problem with the way it handles your identify. Currently, Google ties your Google+ account to a single Google email account, which is not the way most of the other big social network sites do it--they typically let you assign a primary email account, have secondary accounts, and don't force you to sign in or use your email address as your userid.
As Facebook has slowly ruined what little interface consistency it had, I'd really like to see Google+ become a viable alternative, particularly for business use--Facebook is wretched in that regard. But Google+ still has some growing up to do.