Leon,
For me, it behaves very inefficiently. It generates thumbnails to 2 folders deep as I navigate through folders, and won't let me continue navigating until it finishes generating he current set of thumbnails. For me that's a killer - I organise my files in folders of year then shooting session/subject/whatever, so if I navigate to the 2007 folder it tries to generate thumbnails for something like 50gig of files before I can move on. Over a network (mass storage device). And then it doesn't remember the thumbnails and does it all again when I come back next time.
I run on a 2.0 gighz laptop, so it's not new but isn't a snail either.
I just find it frustrating to use because it could do things so much better. I don't care about 2 levels of thumbnails.
I can't remember now, but I think it either doesn't have a non-thumbnail view or it always switches back to thumbnail view.
I find the added features and smarter working of the Digital Photo Professional program canon also installs much much better, much more efficient and more information available to me easily.
I suspect it's also a case of just what you get used to and learn to use. Everyone has their preferences for whatever reason, it's just annoying to be forced to have this open after every download from the camera.
I think suggestions from people here will solve my problem but I haven't had a chance to play with it yet.
Roger.