Debian or Ubuntu for a desktop box?

[Alex Dean]

Hi all.  I've been using Debian testing for a few servers for a  
while, and I really really like it.  I've been using RHEL4 for a  
desktop machine, and I've decided I want to replace it with either  
Debian or something Debian-based.  I've installed one Ubuntu desktop  
machine, and it went very smoothly, so that's fresh in my mind as I  
debate which distro to choose.

I'm wondering what are the principal differences between Ubuntu and  
Debian?  I know Ubuntu is 'Debian based', but I don't really know  
what that means.  What's been modified, and will I care?  The only  
reason I hesitate to use Debian itself is just because I have no  
experience configuring an X server, and having a little friendly GUI  
handholding for that part is appealing.

I am basically Linux-literate and willing to tinker.  But, for the  
desktop box, I also really want something that 'just works'.  I don't  
want to notice it, I just want to use it... to tinker with the  
server. :)

Any thoughts, observations, etc. are welcome.  I am not trying to  
start a RH vs. Debian thread, so I do ask that replies be limited to  
comparing Ubutntu and Debian.

thanks!

alex
.