I have been playing around with the microtype package for PdfLaTeX. The results are really nice. Using the font expansion does increase the size of pdf a tiny bit, but not much. It is definitely worth it I think. Overall using the microtype package, I seem to be getting better line breaks, especially in tight places where there are floating figures (where text flows around them). To use simply add
to your file, and make sure to use pdflatex rather than latex and dvipdf.
What it does is two things. Firstly it will add protruding punctuation (say periods actually hanging off sides of your paragraphs) to make a more straight looking justification. Furthermore, it may “stretch” the font by a tiny bit on certain lines to get a more even “greyness” of the text (for example, getting more uniform inter-word spacing). It also gives the justification algorithm more freedom in finding better line-breaking points, so you generally get better line-breaking (less hyphenation, etc…). It is the font stretching that adds a bit to your files since you need more copies of the font in the file, but the size increase is not terribly big on large files in relative terms. Still with microtype and PDF1.5, the 2MB differential equations pdf goes down by about 200k compared to no microtype and PDF1.4.
Speaking of the notes, it is interesting that the real analysis notes are now downloaded more frequently by new unique IPs than the differential equations. On average about 30%-40% more. That is surprising, I would have thought that real analysis (taken almost exclusively by math majors) would be less interesting to “the masses,” rather than differential equations on the level of calculus (taken by almost any technical major).