2nd ed has a lot of GOOD stuff going for it and I think that it is just fine for Superhero games. I REALLY wish that they had not changed little things throughout the book, just for the sake of change because they throw us all the time BUT they are not bad, just different. I also don't like the redundant Powers (i.e. "Weather Control, see Environment Control" what?)
In the end, for me, I like 2nd ed just fine for Superhero gaming and 1st ed for non-supers games (although I like True20 even better for them myself). Power Level limits is a very cool concept in the mid-range of the game (8+) but for lower games I don’t think it works as well. But that is all just my option and all