How difficult would it be to implement some way to show indentation levels in an unobstrusive way? Sublime text and other modern editors do this by drawing a thin vertical line down from (back-to-indentation). I find it really helpful when reading code. This stackoverflow question clarifies what I'm after, although I didn't ask it. I find this really helpful when reading a piece of code with many block levels, especially since the standard indentation level for ruby is 2 spaces.
I guess it can be faked by changing the face of that column, but that would be more obstrusive than a thin line. Maybe there is another solution I haven't thought of?