Core Data is hairy because it solves real problems - You should use Core Data. If you are using RubyMotion to solve real problems, with a real data model, and complex data relationships, you need Core Data, and I am certain you will find this book saves you hours, if not days, of research time. Even though this book is mostly focused on RubyMotion developers, iOS developers of all languages will find the Core Data SDK-based approach demonstrated here to be an informative peek into the innards of the Core Data.