ScreenFlow was recommended to me by my boss, Seth Long (and before the FTC sends a hall monitor after me, let me disclose that I don’t have any material connections to ScreenFlow and my company picked up the tab) and I have to say that I’m quite happy with it. This being my first-ever screencast, I was happy to have something simple, without too many bells and whistles.
If you can make your way around iMovie, you can figure out screencast pretty easily. (If, on the other hand, you’re in need of more advanced options, I’d keep looking elsewhere.) I’d say the whole recording embedding in that video took me about two hours, but most of it was spent on re-takes (I did a lot of uh-ing and went back to fix it)—the editing and adding of “special effects” was really fast and simple
I’ll acknowledge that it’s not cheap on the individual level, but if you’re doing screencasts all the time, $100 could be a steal.