Hands down, this is the finest piece of video cataloging software available for the Mac (and thusly, the PC). It is as easy to use as iPhoto and includes a very freindly set-up assistant.
It's best use is for viewing your video catalog at a glance - each file is represented by a single frame from the movie. The single frame is set automaticaly via the preferences, or set later manually. You can set iTune-like star ratings per video, which can also be displayed in the "thumbnail view".
The most important feature for me, was being able to keep my videos where they are - I'm sure if I took it on fully, I would allow iVideo to manage my video collection for me.
One sore point is the navigation and interface when playing back a movie within iVideo. It's not very clear how to get back to the thumbnail mode, and changing the display size of the movie can only be done after exploring the menubar... In other words, common tasks related to movie playback are not available; instead the interface leans towards iVideo related tasks (like setting the video's star-rating).
In geneal, this app would do well to follow the iPhoto interface more closely. This includes, optional shadows behing thumbnails, having mode buttons at the bottom of the window, etc, etc.
One enhancement that would bowl me over and really tout the power of the Mac OS, would be to play the selected thumbnail(s) in the gallery view, at their thumbnail size. In other words, why be forced to double click (play) a movie when all you want to do is preview it? Also, if column view does this in the finder, why not a full-on app like iVideo?
Wonderful app, and well worth the price.