I'm using it. I plug my Panasonic HCV100K cam into my MacBook Pro. Go to the folder that has the iFrame files. Drag them onto my desktop. I open up iMovie HD (6.0.4), create a project. (I'm not sure if 920 p or 1080i is best...) Save and close it. Control-click on the iMovie file (package) I just created. Open the Media folder. Drag the camcorder files into that folder. Close everything up. Double-click on the iMovie file. It opens up and says it has found files in the trash. I view them, drag them out of the trash into the clip viewer. Save iMovie. I'm ready to edit with them.
You can do this with many other types of files too. I used to use iMovie HD with my Sony minDV camcorder but I have also edited many other types of files this way too.
It sounds like a lot of steps but it really is fast and easy. Much faster than importing via the File menu.
(Since I can't edit this post, I'm replying...)
On my camcorder, I choose the .mp4 files, not the .mts files. I think, without looking at the cam, that they are in a folder on the cam labelled something like DCIM. There is also a PRIVATE fodler. That has the AVCHD files, if I've recorded any. Those can used too if re-wrapped, if I am correct, but I just using the iFrame (mp4) files for now. (Media Converter http://media-converter.sourceforge.net/ is what I use for the AVCHD files. Fast, simple, free.)
We need to have a iMovie HD site somewhere. (The unofficial iMovie FAQ (http://www.danslagle.com/mac/iMovie/) isn't as helpful as I had hoped.
iMovie 6 Help:
This MaciLife PDF is also good:
There is also a video tutorial here (with links to others):