G'day Leon, the 350d is awsome for both astro and terrestrial use.
It is a pleasure to use and learn the ins and outs of basic photography.
Comparisons between the 350 and other cameras, see the canon come out on top in most aspects.
Even for a beginner it's a breeze to shoot and master its functions.
As for an astro camera, it does a pretty darn good job of capturing all the popular neb targets even the fainter ones unmodded used either, prime focus, piggybacked and even tripod mounted.
I am more than happy with the results this camera has given me, it definately is "that good".
Here is a link for a side by side comparison of the 350 and the 30d
http://www.dpreview.com/reviews/comp...s350d&show=all
Good luck with your choice.