I have chrome for checking things quickly, because, yeah, it is fast as fuck.
I have firefox for heavy-duty internet browsing, cuz i have it uber-customized with scripts and plugins.
A good one is "Hyperwords".
I just select any text, and this lil menu pops up, with WHATEVER I want in.
instantly in-line converts any currency, temperature, weight, mass, volume, distance, area speed etc. also instant inline translations between any language pair.
say its the title of a film, can instantly open tabs in background for the imdb page, the amazon page and, say, a demonoid torrent search for it.
dont know the meaning of a word? wiktionary is right there.
same goes for wikipedia, britannica,
the best thing is that I can add ANY search field i encounter. i just right click on the bluelight search field and click "add to hyperwords".
after that, anywhere on the net, i can search bluelight for any bit of text, at two clicks.
thats just one of many, many plugins, which now mean firefox takes something like 30 seconds to start up sometimes, hence my need for chrome.
IE is a piece of shit.