I wanted to record what I show to people regarding how they can do certain tasks on a Mac. Therefore I checked what Screencast applications are available for the Mac.
I stumbled on the following site comparing several applications, as well as this site giving some tips on how to do Screencasts and which are nice tools to help you doing them, such as Backdrop .
I finally decided to buy Screenium, because it seemed to have the most features for a reasonable price of only $20. It allows to fade in some text via hot-keys and also can embed the feed form a webcam aside the screen that is being recorded. Finally the recorded Screencasts can be easily exported to more compressed formats. It works fine with 1920x1200 resolution and does not use much resources when you record with 100%, not scaling down while you record. You always can afterwards reduce the resolution and optimize the overall file size of such recorded movies. So far I'm happy with it. It's easy to use, not overwhelmed with useless features and works very reliable.