I now use 4 ladders and like to scan across them to monitor the relative moves and to spot any sharp moves. The closer together the ladders are, the easier this becomes.
I was looking at the window and noticed there is a dividing line between the ladders which isn't really necessary and could be removed - the scroll bar acts as a natural division between the ladders.
I knocked up before and after pics in Photoshop to show how it could look...
Before:

After:

The change as above would save 15 pixels for each additional ladder, i.e. 45 pixels for 4 ladders. I know that this seems like a very minor thing, but it's the little things that make the difference.
Regards,
SF.