@jws First of all, imho Alamofire is super awesome. With it you don't even have to set up anything, just create a request object and put in the parameters you need.
Realm is even more awesome. No Core Data stack, no NSManagedObject and all the other stuff used in Core Data.
With those two libraries I sped up my dev time significantly, focusing on the things that matter.
I use Realm mostly for caching posts so the user isn't presented an empty table view at launch.