I haven't actually gotten a chance to see it on its feet yet, but from reading the rules Powers for good seems like a simple, fast, and low prep option for running super hero games.
Character creation is dead simple. Emphasizing troop style play the group as a whole creates a team and peoples it with super heroes. These heroes are loosely defined by their powers and a few key character elements. The game favors troupe style play, and players can switch characters between sessions easily.
The game play focuses on fast resolution and resource management. A diminishing die pool mechanic is used in a clever way to give the game play some depth.
All in all I'd highly recommend it for anyone wanting a good engine to play around with Legion of Super Heroes or X Men style super groups. While the game suggests that Justice League would be another option the game doesn't have any real way to model the difference between a Superman and a Shining Knight.
[4 of 5 Stars!]