Is Canon Digital Rebel XT enough camera for me?

[coolmoon]

I have used an EOS Rebel X regular film camera for years and years and have been very happy with the pictures. My digital camera has been a Sony point and shoot. It is now time to get a digital slr. Is the Digital Rebel XT enough camera for me? What am I leaving on the table by not stepping up to get a 20D or 30D in layman's terms? I am limiting myself to Canon because my father has many Canon lenses that I will be able to borrow (he has a 20D and I assume the lenses will work on the Rebel, please correct me if I am wrong).Thanks