[I'm using the 0.4.0 package from Ubuntu Breezy]

The "fit to page width" option includes the page margins when calculating the zoom level. This leaves a lot of wasted space on either side. It would be nice if there was an option to crop closer to the actual text width.

As an example, have a look at this research paper:
http://www.hpl.hp.com/techreports/2002/HPL-2002-82.pdf

When "fit to page width" is selected, it looks something like:
 ______ A line of text here. ________

Adjusting the zoom level manually is a reasonable workaround, but it would 
be nice if I could get to the following without a lot of manual tweaking:

__ A line of text here. __

An even better solution might be to zoom in until you reach a "natural" point size for reading at the monitor's specified DPI -- the real problem is that the font is often too large or too small for easy skimming for each new document.