Google+ has some advantages. For one thing, you have more control over your experience. And your feed isn’t cluttered with ads. In general, Google+ feels like a cleaner, nicer place than Facebook, which has never been very attractive and is starting to look old and tired.
Ironic that a feature of a Google product is, at least for now, the fact that it's not "cluttered with ads". I can't see that lasting forever but it's a nice counterpoint to how ugly Facebook is.
The bigger news, however, is that Google+ now has 500 million members, 135 million of whom are active users of Google+ itself, while 235 million are considered "active" by virtue of interacting with Google+ from other Google sites. That total number of 500 million is up from 400 million only three months ago.
I get tired of people on Twitter/etc. cracking "Remember Google+?" or "Is Google+ still around?" jokes just because they haven't figured out a use for Google+. I'm not very active on there right now either but you can't deny that a lot of people are finding real uses for Google+, particularly photographers.
Their new Communities feature (essentially groups/forums within Google+) is only going to help that growth as more people are able to gather around similar interests.
I'm the last person who wants yet another social network to come along. But just like Google and Microsoft with Apple in the mobile phone space, competition is a good thing. A company that has dominance in a market eventually gets stagnant and looks out only for the bottom line and not what the users need or want in their products.