Originally Posted by thetruth
Is either Firefox or IE any faster than the default browser?
This doesn't affect the speed of the browser directly. All this does is change the identification (or user agent) that your browser sends to a website. Therefore, when you have Firefox enabled, the website thinks you're viewing it from a full version of Firefox and gives you the full page.
If anything, switching to Firefox or IE will make your browsing seem slower on sites that you've previously been getting a mobile version for because it's going to load the whole site now, not the mobile version.