I have done a lot of dabbling with Cocoa in the past by fixing application bugs and going through sample apps from books, but this is really the first time that I am starting an application from scratch. My first impressions? I love it. You can really see how there was a lot of design work in the Cocoa APIs. It is much nicer than any MFC or Win32 I have written.
The other thing that I think is cool is I have had to do a number of Google searchs to find APIs to do what I need and the search results point me in the right direction really quickly. I couldn't always say that about Windows. Half the time Google searches for Win32 or MFC type stuff always pulled back crap info or stuff that really was better implemented in C# or one of the .NET languages. I remember it was pretty often that I'd have to "port" something from C# to C++ because the C++ APIs were not very well documented, but still were similarly implemented in .NET. That kind of stuff got really frustrating after a while. Inevitably, I always ended up going to Codeproject or Codeguru and drilling down deep to get the info I needed... if I could even find it.
I am sure there will be some things that will drive me crazy about Cocoa after a while, but for now I am just enjoying the research and learning something new that for now "makes sense".