I just upgraded to Firefox 6 on Ubuntu. The new version doesn’t have any major interface changes but is 20% faster than Firefox 5. Startup time has also been improved especially for those like me with a lot of tabs and groups. Firefox 6 uses about 8% less resources than the older version so it doesn’t torture your resources as much. Firefox 6 handles zoom better and looks a lot cleaner when you zoom in on a page.
It’s this easy:
* sudo add-apt-repository ppa:mozillateam/firefox-stable
* sudo apt-get update
* sudo apt-get dist-upgrade