i am a professional photographer and i have many different cameras.
in terms of SLR's and Cannon i use the Cannon 1DS MarkII for sports photography. i think that this camera is a little bit over the top being that you are looking at a 20D and that it is priced at almost $7,500 for the body, but this is besides the point ..
(1DS MarkII)
If you are looking for overall user experience with the Cannon SLR line .. overall, i am very impressed with what Cannon has done with their digital SLR line. all of the buttons, knobs, etc are very easily accesable and very easy to figure out. the image quality is amazing once you learn the different features that you can use with the camera (white balance, image quality, etc.). pretty much Cannon is love. you will be constantly finding new things about your camera everytime you go out and use it.
to get to the point, you will be very satisfied with Cannon. i'm sure you looked into the Nikon D70 when you were comparing DSLR's. one word of advice, don't even think twice about your 20D. if you are planning on sticking with digital photography Cannon is most definently the leader of the pack.
great purchase, and i hope you enjoy