^ This.
Google+ will allow you to automatically upload your photos to Google's servers. This is not the same thing as Drive, mind you, but because of that it doesn't impact your storage limits of Drive, either. None of your photos will get posted anywhere. They're tucked away on G+ until you decide to share them, if you ever do. Outside of using Dropbox, it's the easiest way of backing up photos to the cloud.
If I were a betting man, however, I would put money down on Box adding that feature before too long if you really dislike G+.