For the past several years, I've been using pdflatex to generate PDFs from my LaTeX, and it usually works like a charm. All modern versions of pdflatex correctly use type 1 (vector) postscript fonts and not type 3 (bitmap) fonts.
Just today, I was generating a PDF for a camera-ready, but whenever I looked at the list of fonts in the document, I kept seeing type 3 fonts there. I couldn't figure out where those type 3 fonts were coming from. I initially thought they might be from some figures, but that ended up not being the case. After playing with my document for a while, I discovered that the problem was that I was using some non-English characters, which was causing problems for LaTeX. Apparently my default installation of LaTeX had type 1 fonts that only covered the standard English character set (plus some accents). When I used characters like French guillemets quotation marks, LaTeX would need to use type 3 fonts because those were the only versions of the fonts with those characters. Using \usepackage[T1]{fontenc} did nothing since my LaTeX installation simply didn't have the necessary fonts.
Fortunately, there is a package called cm-super that seemed to contain the necessary fonts. I couldn't figure out how to coax my Fedora TexLive distribution to download this package, so I tried to grab it in Windows using MiKTeX. Unfortunately, the package is fairly large, and MiKTeX kept killing my computer while trying to download it. The download would start quickly, but gradually slow down to a crawl while my cpu utilization would go upwards. I suspected MiKTeX was doing something silly like storing the file in memory, but in a linearly expanding buffer of some sort. My Thinkpad X61t has always had heat problems, and running with high cpu usage for such long periods kept causing my laptop to overheat and die before the download would finish. Fortunately, I was able to download the packages plus some index files directly from a mirror, and get MiKTeX to load the package locally instead of from the Internet. Some people also needed to do the usual MiKTeX oddness to get things to work right afterwards.
But everything seemed to work ok once I had cm-super installed. My PDFs contained only type 1 fonts. I really don't have a strong understanding of why cm-super isn't included in my default LaTeX installation. Are the fonts too big? Is the quality of the fonts not as good as the default ones? I have no idea. But it looked ok to me, so I'm going with it.
