I would like to use the entire area of my monitor to see my photos. As it is, LR4 always steals some space from the four edges of the screen for the collapsed panels. On top of that, photos in "fit" mode get another margin between the panels and the photo.
There should be a way to get rid of the edge bars for the collapsed panels. They are essentially very large buttons and are unnecessary. Moving the mouse to the edge of the screen could accomplish the same thing. (you could still show them in the click-to-expand mode)
The "fit" mode should get rid of the extra margins. I know they look pretty, but form should follow function and not the other way around. (perhaps make it an option).
If you do the math, the collapsed panel bars and the margins take up 13% of the screen
PS: THIS HAS NOTHING TO DO WITH LION'S FULL SCREEN MODE PLEASE DON'T MERGE MY TOPIC AGAIN.