Have been using Swift since late 2014 (having used ObjC for many years prior to that). Even with the occasional churn (eg move to 2.0 or 2.1), the sheer gain i

Have been using Swift since late 2014 (having used ObjC for many years prior to that). Even with the occasional churn (eg move to 2.0 or 2.1), the sheer gain in productivity due to brevity, type checking, cleaner closures, and various other language features, easily outweighs any costs. I find myself being able to do more with less code, and cleaner code. It's cognitively way easier to build bigger abstractions. We do have a few legacy bits that makes no business reason to port at this point, but Swift-to-legacy interop works well, too. I would say the biggest step that made things usable was introduction of incremental builds in 1.2.