Just a comment. Firefox isn't going to be able to compete with the highly-optimized built-in browser. This is for people who want all the bells and whistles that come with a full Firefox browser, and are willing to put up with the browser being a bit slower.

I suggest trying the package out; if you have broadband internet, it will take about an hour or less to download and install. I recommend switching the CPU to "performance" before starting the download, it will really help the unzipping part.

If you don't like it, uninstall the package and delete the big file.