I am a huge fan of Fiasco, and it's one of my go-to convention/one shot games due to its simplicity and the way it almost always generates great play. So getting the new Fiasco Companion was a no-brainer for me.
The book is mainly filled with advice - some general and some specific, such as convention play advice or how to build your own sets.
I used the advice on convention play yesterday, and it was all good. Those two games got into gear a bit quicker than I was used to, and both were really good fun.
There's also four new sets included, and a softer version of the tilt/aftermath tables that can be used for games that are aiming more at "comedy of embarrassment" rather than "death and mayhem". One of the games I played yesterday was "Regina's Wedding" using the soft tables, and it was really good fun. It definitely captured a lighter but still hilarious feel (it was a bit like a wedding version of "Death at a Funeral", indeed we even included a naked drugged character who would have been played by Alan Tudyk).
Overall, the Companion is a solid chunk of new stuff for the money and anyone who plays Fiasco regularly is sure to get their money's worth out of it.