Don't install!
FF3 might be the bees knees but it disables several features from other browsers. My Real Player downloader, my dictionary, and my on-line picture editor have all been disabled so I have deleted it!
That's a wee bit concerning! I don't like Real Player, but the downloader has been very handy as it will often find things that DownLoad Helper won't. I'm getting a bit wary of automatically updating to latest version of everything, far better to wait and see what others find out first.