I think it is faster then Chrome with add-ons or at least just as fast. I had to stop using Chrome once people started making Chrome only websites and pushing it even though other browsers had the same capability. Chrome is a good browser but so is Firefox, IE 9/10 and Opera. Each one is faster at different things so there will never be a clear advantage like 2009.
Likewise, can somone email me when Chrome stops cutting corners? When developing, out off FF, Opera and Chrome, Firefox is the most consistent and asthetically pleasing. Yes, Chrome is usually the fastest when it comes to raw speed, but as long as it is cutting corners (for example, try rescaling an .svg with javascript, or make a gradient that extends over a few thousand pixels, and see how blocky both become), it's really comparing apples and oranges.
You need to compete on all fronts and decent UI is one of them. Firefox, for me at least, is still behind in this area (though I loved the Australis stuff that was being put forward).