What do I like about it? All the mutations appear immediately gameable. They are categorized in a way that lets you roll to select a specific type of mutation. And they are system neutral, working with whatever game system you are using.
Oh it's free! You can download it from Lulu here, or purchase a printed copy here, or download it with even less hassle from here!
As an aside, the authors would like you in exchange for their free document, are looking for information on a vetted charitable organization that addresses the violence surrounding coltan mining in the Democratic Republic of Congo. More information is here.