I just upgraded from the D30 to 20D... simply put, the D30... while a great camera is a dinosaur! I had to upgrade considering both a) the increased resolution and b) much much much much better noise performance. The d30 is so behind that I can *almost* not use it as a backup
I finally found a good use for my D30 after it's sat on the desk for a few years now holding down all those bills........ http://www.flickr.com/groups/cameratoss/