My experience has also been the same.

Chrome on the mac is absolutely dog slow to use, especially after you open up a few tabs. Seriously, why do people say it's fast? I really don't get it. It was fast at one point but now it feels slow, bloated and the tabs crash far more often than either Firefox or Safari. If I only had a penny for every time I see the sad face on tab crashes.

Firefox has no lag whatsoever when switching tabs, and general usage. Maybe people think it's slow because of its dated UI? Maybe they haven't used it at all? Maybe they're still using Firefox 10 or older? Firefox 22 is awesome. People just need to give it an unbiased try.

Safari is the fastest of them all, both in rendering speed and general usage, though it tends to use a LOT of memory.

I honestly wish I could use Firefox as my development environment. I prefer Firebug to the Chrome dev tools. But I've been slowly forced to admit that it can't keep up. With Chrome, I can casually open up a dozen tabs without considering the consequences; in Firefox, I get worried when I have two open. This pans out in the Activity Monitor.

There exist huge inconsistencies in all of these claims, and it's extremely strange how difficult it is to work out what third variables are involved that are causing such vastly different reports.

I have heard reports of considerable performance improvement from users clicking on "Firefox Reset" button. Have you tried it? You can find it in about:support (or somewhere in the Help menu, I can't remember where).

Chrome is very fast on my 4.8Ghz Windows PC with literally hundreds of tabs open sometimes. Almost as fast as Waterfox. If it slows with a few tabs my guess would be the OS is swapping Chrome processes memory to the swap file (or files). FWIW I just put 32GiB in my machines and remove all swap files.

Yes, Chrome is very sensitive to swapping, performance-wise.

Mine is opposite your opposite. :) On my 2.5GB, 1.8GHz Core Duo Thinkpad from 2006, Chrome handles dozens of tabs in multiple windows like a champ. Firefox pre-24 was noticeably slow with just a few tabs in a single window. It's been unusable for me since 2011.

In Firefox, have you tried "Reset Firefox", in about:support? Most users report that this speeds up Firefox considerably.

Thanks, I'll give it a try.

I find that this kind of behaviour is symptomatic of a machine which has a slow hard drive. Have you run benchmarks on your disk? What kind are you using? (SSD? Magnetic 3.5"? 2.5"?)