I have done a few months of development with Qt (built GUI programatically only) and am now starting to work with Cocoa. I have to say, I love Cocoa. A lot of the things that seemed hard in Qt are easy with Cocoa. Obj-C seems to be far less complex than C++.

This is probably just me, so: Ho do you feel about this?

How does Cocoa compare to WPF (is that the right framework?) to Qt?
How does Obj-C compare to C# to C++?
How does XCode/Interface Builder compare to Visual Studio to Qt Creator?
How do the Documentations compare?

For example, I find Cocoa's Outlets/Actions far more useful than Qt's Signals and Slots because they actually seem to cover most GUI interactions while I had to work around Signals/Slots half the time. (Did I just use them wrong?)
Also, the standard templates of XCode give me copy/paste, undo/redo, save/open and a lot of other stuff practically for free while these were rather complex tasks in Qt.

Please only answer if you have actual knowledge of at least two of these development environments/frameworks/languages.