Having read through Zounds!, I'm impressed. I've been gaming for thirty-someodd years, and have played or GMed a lot of systems. I found SFX to be nicely minimalist in its mechanics, with a heavy reliance on the concept of plausibility for the setting. The game puts more of the weight on the players than most systems, creating a more cooperative environment between GM and players, pushing the game more toward group storytelling and away from improvisational acting with a stage manager. I look forward to having the time to read through the other three of the SFX games, Kapow, Zap, and Argh.