I use the HHKB Professional 2, White, Blank, American Dvorak layout (with the numbers numbered 1-9).
I have delete set to delete (btw if you want to set delete to backspace, you can still use fn+` to mean delete), the left small modifier key to super (manages my window manager), the left bigger modifier key to alt (used as meta in emacs and other programs), the right bigger modifier key to altgr for some extra characters and the right smaller modifier key I hardly ever use. I've mapped some weird stuff to scrolllock, pause and printscreen, as well.
I like this keyboard very, very much. I only wish it didn't have the logo down in the right corner.