When I've looked in the past, Interface Builder was (as far as I could tell) a first-step-and-don't-return thing. Meaning you could lay out an interface visually, but when you want to start coding it becomes a code definition of that interface, and once you start updating that, you can't (easily) return to the visual interface-definition interface. Has that changed, or was I wrong?

Sadly, that's what it has turned into.

Used to be a lot better.