Swift 3 is a thorough refinement of the language and the API conventions for the frameworks you use every day. These improvements make the code you write even more natural, while ensuring your code is much more consistent moving forward. For example, select Foundation types such as the new Date type are easier to use and are much faster than previous releases, and the Calendar type uses enums to feel more at home within Swift.
Lead Engineer (iOS) @ Dainik Bhaskar, devswiftable.com
8ySwift is more powerful language now.