I work on a desk without trays - the keyboard too high is a big problem for me. And trays (IIRC) aren't very sturdy/mouse friendly. So I'm thinking about having a low table when I move again.

Also, it seems to me that the old rule "top of monitor in the same height as your eyes" is actually a more personal "whatever works for you" thing. See discussion at http://superuser.com/questions/231377/whats-the-correct-moni...