Waterfox is much faster on a 64 bit machine! Waterfox uses your Firefox profile so you must be careful when uninstalling Waterfox making sure you don't have the remove personal data box ticked.After using it though you probably wont want to uninstall it
Firefox 64-bit is a "constant source of misunderstanding and frustration," the engineer wrote that the builds often crash, many plugins are not available in 64-bit versions, and hangs are more common due to a lack of coding which causes plugins to function incorrectly.