Speed of browser
Security for you
Firefox 64-bit allowed the private browsing for the first time via which you can browse securely and hidden. You can fully remove or clear the History, searches, passwords, downloads, cookies and cached contents. If your power gets off it automatically removes all the content on sudden shutdown. You will experience a safe browsing.
Development and Personalisation
Firefox 64-bit have many features which are best like customization etc. All you have to do click on the navigation toolbar and customize the content you want. Other method is drag and drop one. In this one you have to simply pick up the content and then drop.