I gave the reasons we went to Canon for a DSLR way back in post #4.
A quick history of our digital cameras is as follows:
 Early Casio: less than VGA resolution, but one of the best for under $1000 (barely).
 Sony Mavica: VGA resoultion and storage on a floppy disk. Wound up doing such a good job (for the time) that the Arizona Department of Corrections (for whom my wife worked) purchased several for recording prisoner identification marks and temporay id badges for work details.
 Sony Cybershot: with 2MP resolution and a good 400mm+ zoom lens, our first birding camera. Actually quite good.
 Nikon CoolPix 5700: very good 6MP camera for the $$$, but very, very poor manual focus system (had to reset for each shot).
 Casio Exilim: 8mp, good camera overall, but terrible for our purposes (birding), bad choice on my part. We got it as a pocket-sized backup to the Nikon, and sold it for a song in about 6 mos (along with aux wide-angle & telephoto lenses).
 Canon EOS 20D: excellent 8.2MP camera (now our second-body camera).
 Canon EOS 30D: another, even better 8.2MP camera (our primary camera).