Continuing my work on making a Debian desktop that works out of the box using preseeds, I took a look at the condition of the GTK+ graphical installer for Debian Lenny Beta1. If you haven't tried it, you don't need to rush to make a special attempt.
Executive summary: It's the same as the text installer, but using GTK and a mouse. There's no difference except that I find the graphical installer more time-consuming if you use the mouse. If you don't use the mouse, then why were you in the graphical installer at all?
If you really want to try it out, grab the Lenny Beta1 businesscard.iso and give it a whirl. Type installgui at the prompt in order to get the gui. Just type install for the traditional text installer.Compare the two in screenshots below.