Having loved 35mm and done several year-miles on smaller digital cameras, it was time for a digital SLR. I'm glad I got this one, even though the 20D was announced only a few months later.
The layout is intuitive and very easy to learn, and the camera produces great quality images. I absolutely love the 10D.
Fall-downs are the extreme slowness of RAW (4 seconds on a 40x Lexar CF) and the horrid software "suite" from Canon. It cannot be bludgeoned into naming files my way, nor does it pick up a CF card in the reader without the camera (my Nikon Coolpix software always worked 100%). Then instead of one integrated application, there are 2 or three disjointed "viewers" all jostling "pick me, pick me". I now use 3rd party software exclusively for all my work.