I love MagicalRecord. Not only it makes working with Core Data much easier, it makes writing Core Data unit tests a joy.

For those who don't know Magical Record, here's basic a tutorial:

http://ablfx.com/blog/article/2

It's worth checking mogenerator as well:

https://github.com/rentzsch/mogenerator

http://raptureinvenice.com/getting-started-with-mogenerator/

I love the helpers for fetching and creating records that MagicalRecord gives you. But MagicalRecord also has ideas about how you should structure your ManagedObjectContext hierarchy. In the older versions (which we're still using) it was simple with just a separate context per thread which is connected directly to your persistent store. But the latest version (at least last time I checked) is much more complex with multiple child contexts rolling up to your persistent store.

I would prefer to just use the helpers and setup my MOCs and persistent store myself.