If you have not updated yet, you will be very surprised when you finally do. There are a lot of changes. Don’t get me wrong all of the changes I love, it just gets some getting used to. The biggest change is the looks, the Firefox button now contains all of the menu items, it makes it easier for me since it is all in one place. 

The bookmarks you can now manage with one click. They are located on the right side under the search bar. The reload and stop button are now one in the same. The home button moved to the right side, after the search field. I am still getting used to this.

The most awesome of all things the new app tabs are awesome. You can basically leave all your favorite sites open all the time and not take up all that valuable tab space. You can also all of your tabs by right clicking and selecting Reload All Tabs.

Firefox also has improved speeds and they revised some of the JavaScript managing and also now supports ECMAScript5 and building the brand new JägerMonkey JavaScript engine.

So if you have not updated go and do it, you will have a prettier Firefox and improved performance.