I usually read WP at home through a 28800pbs soda straw and here is my
experience using Firefox 2...
Trying to load a WP page the first time the browser is started or
after clearing the cache is dog slow. After that they load reasonable.
If during an initial "dog slow" load, the modem is disconnected, the
page pops right up.
Someone on IRC said this might be because Firefox and most other
browsers always wait for all CSS to load before rendering the page and
it might be the codepages that are loading slower then the main text.
Future loads are faster because the CSS is cached. Same person also
claimed that this has been corrected in Gecko 1.9 but I noticed no
difference when reading WP with a pre release of Firefox 3.