minor tips, in case you haven't seen them elsewhere:

- unless you're really a fan of firebird's smooth-scrolling, turn it off; it's slow (general.smoothScroll) compared to IE

- by default, the self-imposed delay of time between the time it starts receiving data and the time it starts doing layout/displaying is set rather high for many people; if you have a moderately fast machine + internet connection, kicking it down helps a bit. (nglayout.initialpaint.delay)

both of these can be set in about:config. i'm running win2k on a disgusting via C3; after tweaking these, firebird beats IE on general navigation/layout speed here..