KDE 4.1 is suposed to be "a great one" usable by most people but if you have tested betas are you missing something?
I do. I miss an update of knetworkmanager and kbluetooth. These apps have not much interface so it shouldn't be hard to just keep the model and change the view. You could say that you already can use it but it is a showstopper. Also packages in distributions for KDE won't depend on them and their KDE won't be completed when you for sample type "apt-get install kde4". Looking for information I found that these packages are the chosen ones for KDE4 but I cannot find something like a subproject page at kde.org. These apps don't seem to be part of KDE.
What are you missing in KDE 4.1?
One thing that would really change my mind about KDE4 is if the text configuration file for keyboard shortcuts were set up in a way that made it possible for me to directly edit it, similar to fluxbox. The GUI interface for setting up shortcuts in KDE4 makes me want to cut myself. I tried editing the file as it is now, and I got unsatisfactory results.