Yes, as part of a project that has used Swift for the last year, migrating away from Objective-C on a decent size codebase, I can say it is not ready for primetime.

Swift 2.2 + Xcode 7 wasn't great, but it was livable.

Constraint SourceKit crashes makes Xcode essentially a text editor and not a good one. All indexing, highlighting essentially all IDE functionally lost.

This is the worst development experience that I've seen in 20+ years as a developer.

I thought the CoreData / CloudKit debacle from 3 years ago was bad, but oh my God, I just want to jump ship and go to Android, switch to Xamarin, or just leave mobile at this point.

It would be nice to have some level of optimism and say this is growing pains, but I don't have any faith that the Apple developers are competent in making this better.