[mdhughes]

Swift devs keep saying it'll get less fragile, then they rewrite "exceptions", or how strings work, or anything else and all your code has to be fixed line-by-line. I do not believe it'll be stable this decade.

Xcode stops supporting old features in XIB, or a class has a deprecated and then removed property, and the deserialization fails. XIB is not XML with a nice semantic DTD, it's an object serialization graph that happens to use XML.

[valuearb]

Nah, I switched to Swift at v1.0, the transitions have been relatively easy. Right now our app has 90k lines of code so Swift 3 was a day of work, but mostly automated.

Swift 4 is automatic. The trick to making the transitions easy is to not abuse the language with too clever code. Write clear, straightforward and easily msinatainavle code and it will rarely be broken.