100% SwiftUI! As a new Apple developer, I wanted to use their latest and greatest. It does get restrictive sometimes, but compared to having to dive into AppKit/UIKit hackity-hack SwiftUI solutions here and there are a lesser evil IMO.
Ahh yeah, SwiftUI isn’t fully baked yet unfortunately, particularly on macOS. I’m just now starting to use it in significant capacities in iOS projects and haven’t yet started on Mac because of that.