One advantage is that there are plugins, like YSlow from Yahoo, that are available for Firebug. Though the article notes that plugins don't currently work with

One advantage is that there are plugins, like YSlow from Yahoo, that are available for Firebug. Though the article notes that plugins don't currently work with the Firebug 3 alpha. YSlow is pretty useful, both as a developer and when attempting to demonstrate potential problems with a site's performance to others in an objective way. Besides: a plugin with its own plugins is just cool.