First off, I was always a huge obj-c fan, but I can tell you from first hand development of what is most certainly the largest and most complex pure Swift sourc

First off, I was always a huge obj-c fan, but I can tell you from first hand development of what is most certainly the largest and most complex pure Swift source tree that Swift has many serious advantages over obj-c. I am convinced we could not have such a stable product so quickly without it. It has immensely improved productivity. It has some shortcomings still and sometimes you do miss obj-c's dynamic dispatch, but on the whole Swift is far more than an evolution. I think Apple is definitely on the right track and you will see obj-c getting deprecated within the next 5 years or so. As others have mentioned, ABI stability is the number one issue preventing Apple from rewriting frameworks in Swift.