Any downsides to teaching this way?

Well, yes I suppose there are. First of all, you do have to invest time in learning the software. Thankfully there are lots of (what else would they use to teach their product!?!) video tutorials on how to use Camtasia.

Second, it definitely takes time to make these videos. I've put in many hours making them, and redoing sections if I forgot something. Recording yourself talking and clicking on things sounds easy, but it's easy to mix up your words or "talk yourself into a corner" when recording. I've had to do many retakes of certain sections. Perhaps it might be easier to script out what you're going to say?

Third, you have to have a place on the web to host the videos. Luckily Oregon School District has a web server, so I just upload the videos there. The video files can get large, so you have to have the server space. Techsmith (the Camtasia company) has a spot on the web - Screencast.com - where you can upload your videos, there's a free signup and a "pro" level that costs a bit to join.

One more thing - once you make these videos and something changes "out there" be it software being updated or a website changing it's design or functionality...your video is now out of date and not useful.  Of course the same could be said for detailed directions in paper format, those can get outdated as well.