It depends on your location I guess. I'm from Romania and travel and speak with people mostly in Europe. I've had the same failure you mention with Hangouts. And video quality was never OK whenever I tried, with frames being dropped and so on. Whereas Skype has been OK even on my mobile 3G/4G connection and I'm a heavy user.

In fairness, Skype had a couple of major network outages. Maybe you hit one of those.