I have narcolepsy and definitely don't feel superhuman! I barely feel human at all most of the time!
I am the only person in my family to have this disorder, although I am suspicious that my dad may also have it. However, he has so far only been diagnosed with sleep apnoea.
Also, I would disagree about being immune to addiction. I have good self control when it comes to things like drinking/gambling etc- I can take it or leave it. But I do get fixated on things. Maybe it's just OCD, but it seems like they may have similarities. My medications to keep me awake tend to make me focus on things to the point of being obsessed. Not fun.