I have about four hours into this game, I'm loving it. Much more than I anticipated. Still doing megaton missions right now, getting some things for Moira. The sense of scale and the wasteland setting is amazing. I try to quest during the day as well!
I ran into one super mutant early on....but he was a friendly super mutant! Uncle Leo, strolling the wasteland trying to bring peace and harmony. When I first saw him at a distant, I crept up slowly. I noticed no red icon was popping up saying he was an enemy so I went for it and we had a nice chat!