Chrome is smoother, less cluttered, and all around works better than Firefox (which has fucking memory leaks up the WAZOO). I never get pop ups or spam do to chrome and the simplicity of the browser with the amount of things it still has is great.
I hate Firefox and it's memory leaks and it looks like I'm still on windows 98. Before anyone says "you can get sweet skins!", I don't want to download a shitty skin that requires more fucking plugins that I already DON'T want and most of it is open source. I'm done messing with unnecessary downloads these days... Chrome looks nice and simple to begin with and works in every way possible. It's tab browsing is way better as well.
I was a firefox user for years.