I went through the demo along with 3 friends and 3 strangers. It was REALLY fun, we played with the pre-generated templates that will be published in the book but each created a background, persona, and appropiate super-heroic name. I think we must have taken at LEAST 30 seconds each.
It's a very fast combat system, I'm pretty dang impressed with the mechanics around damage - this isn't a game where Superman will be rolling 45d6 for damage. The character generation is right on from a philosophical perspective - standard RPG superpower customizing - but we didn't really get too in depth with chargen. The question is how well the power costs are calibrated against each other - that's the part that makes or breaks a supers game.
The demo was good enough to keep me from buying several other superhero games at GenCon. In fact, we were having so much fun that we blew off the "Wild Talents" demo that we had scheduled. (Wild Talents is a more generic "supers" game from the makers of Godlike.)
Buy it in October. You'll be glad you did.