I've been using the ruler (with line box color 128,128,255 and line column color 193,193,255) such that the line column ticks are very faint so they don't obstruct the line I'm editing too much. However I've noticed that even this causes portions of characters to be completely overridden making them sometimes hard to read.
As a suggestion I think it would be really cool to have the ruler (or at least the line column) have alpha information so it could always appear over letters but not obliterate them (letters such as capital 'L' in my font have the top half cut off).