The most important thing in the thesis is the actual science. I know this. However, it is really tempting to get anxious about stupid stuff, like the number of pages. With appendices, my thesis is turning out to be quite the paperweight, but the actual number of written pages is somewhat low. Not anomalously low, but less than 100. I have a little bit of leeway in the pagination and text, and I could make the spacing and the typface bigger, increase the spacing around figures, etc, but this makes the thesis look silly after a certain point.
Until fairly recently, my thesis was hovering around the 60-page mark. This had me really worried, although it didn't faze my advisor. So I ran around doing all these calculations and trying to discern more trends in the data and now my thesis has a little more content.
I have a friend who is a mechanical engineer, and we have fundamentally similar theses in that we did something fairly simple to explain (I can describe my topic in five words - I just counted) and a lot of the science and learning (and most of the time) was in getting the damn thing to work. My friend's thesis involves machining something very non-geometric to the nanometer, and his thesis is essentially a short video of a laser cutting away bits of material until you end up with what looks like a misshapen lump. So maybe I don't have it so bad.
I am glad that my thesis isn't 200 pages of "equation, equation, jargon, jargon, jargon, equation". I would like to think it isn't totally impenetrable and dull. But at the same time, I still sort of wish it looked more "scientific".