Good buy, good camera. I'll play devil's advocate on which one to get modded. I have a 30D and a 40D. The difference between the 2 models is significant, much more than I anticipated. Mainly in terms of what you can do with the 40D connected to your notebook while taking astro images. Much more control with EOS Utility, it can be controlled with more functions remotely. So I'd be using the 40D for most of your asto stuff. Mind you, I'm also using my 40D for everything else, too, so will be selling the 30D
