Pure Swift for the new apps. We freak out when we see @ObjC or NSObject usage in our codebase. On a long enough timescale when Apple converts away from using Objective-C under the covers, our code will not need any modification.
…how are you interacting with UIKit?!
I rarely see that annotation or class name in my codebases too.
A quick search through one of my apps shows that about 4% of functions are marked as @objc (and we're not using the old compatibility mode where more methods were implicitly @objc either).