I'm disappointed in how many people are willing to judge Swift as a language without regard to Swift as a platform.
As a language, it's interesting. As a platform, it's abysmal. Xcode crashes, terrible debugger support, the language has many many dark corners, waiting to trip you up and ruin productivity.
Xcode build times have been improved, but it still take 5+ minutes to run our modest test suite. They are not complicated, and all our networks requests are stubbed, it's mostly compile time and just waiting for the code to run. It's painful.
Performance has improved greatly, too, but that only tells half the story. How long did it take to write the code, to test it, to tweak it? With ObjC the compiler was so quick that this cycle was relatively painless. With RubyMotion we have the REPL and it is a HUGE boon to iterating and debugging.
I'm not impressed by Swift, and until Apple improves the experience of working with Swift, I will continue to be critical of it.