Excellent resource for a GM running Dog Town or any other campaign based around criminal activity. This is the level of detail that I want for this type of product. There are place descriptions, maps, and characters included in this gritty setting. More than that, though, this sourcebook provides events to plug into each location along with organizational guidelines and motivations for two competing gangs.
I'm already impressed with the Dog Town rules, but Grenson Park takes this to a whole new level. I've managed to transfer this entire setting to another set of rules, and it works just as well as when I used Dog Town. Grenson Park is maximum bang for your buck.