The most important feature about Diaspora* was that it had no central server, which meant that you were free to run your own server. I've been using this software for a while now and have never encountered any problems with it. It works like a charm. There are some other features which I haven't used so much but they're also very useful. I would say that it's not just great in terms of privacy as you can set up multiple accounts and use them without anyone knowing. You can even share files and images with friends and family.