Do the numbers: if the user doesn't learn to suppress the left nav bar (which they have to do with EVERY NEW PAGE; it is not persistent), then that means out of 800x1200 visible pixels, only 550x800 pixels are my content. So, that is 440K pixels out of 960K pixels: I am getting to use less than half of the visible screen. Ouch.
My actual content is in the red box below: