I've read that a number of times now, but I have trouble matching it to my perceptions. Can you point to a specific website where you notice that slowness and then describe what action is slower? (Initial load, clicking stuff, scrolling, etc.)
Just as an example, loading jslinux.org for me in Firefox is about twice as fast than in Chrome. That might be a special case of course, because it is a very special type of workload that probably is not common on other websites. But I would love to see concrete examples of the opposite.
Put 10,000 or so event handlers with their own DOM updates on a page. Chrome will run it smoothly (taking up a huge amount of RAM in the process), Firefox won't.
Do you have an example of one with 10,000 event handlers? If the case where Firefox falls isn't real it doesn't matter that other sites suck (not arguing that fact).
For our benchmark suites at work, Firefox and Chrome generally trade back and forth on who's faster. It's not a consistent 'chrome is fastest'. I'm sure there are specific websites where Chrome dominates but I've yet to see any evidence that we're still in the bad old days where Firefox was orders of magnitude slower on important stuff.
Firefox is slower than Chrome if and only if your DNS is not responding as fast. When backed by a performant DNS server, Firefox is generally faster than Chrome.
This usually doesn't matter, but you can immediately see it in any page that
A) has a massive DOM
or
B) uses complex regular expressions that eat up the engine