Hmmm - I think this is my first post on the forum...!
They're still very nice cameras. As already pointed out, they won't have the ultimate low-light performance and don't have some of the "now standardised" features of new Canon hardware (in-camera focus calibration, spot metering, etc.), but they still take lovely pictures.
I compare mine to my Dad's 350D on a reasonably regular basis and the images produced are broadly similar, but the 20D is just so much better to use - more ergonomic and more robust.
However, the noise the shutter makes might surprise you.