Core Data Concurrency & Maintaining a Silky Smooth UI
Brian Boyle

What about old-style solution: using two MOCs — master and background independent context using NSManagedObjectContextDidSaveNotification. I suppose that passing data forth and back between worker and master contexts in your case will take a lot of time in a main thread eventhough nested MOCs solution is newer. Even if UI runs smoothly it still can be a bottleneck. Did you make any performance tests?

One clap, two clap, three clap, forty?

By clapping more or less, you can signal to us which stories really stand out.