Hmmm... y'all made me have to go and check/time some things.
Time to launch: (From clicking quick launch to home page being displayed)
Chrome: 0.7 seconds
Opera: 1.2 seconds
Firefox: 2.3 seconds
IE 8: 3.4 seconds
(Intel Q9550 - Quad core @ 2.83GHz - 8GB RAM, NVIDIA GTX260, XP Pro 64Bit)
So, yah, Chrome and Opera win the speed test at launch quite handily. For render times? I really don't notice any difference, and it's usually far more dependant on the load of the server that's sending up the page than on the browser.
But let's look at those times again... The WORST offender (IE 8 - isn't it always the worst offender in most categories?), is still up and usable in just over 3 seconds.
Sure, there's a noticeable difference between the browsers (we've done tests at our company, and most people can "notice" a lag of around .05, or 1/20th of a second for visual input - which is why even high def movies in the theatre still only need to pump out 24 frames per second). But does noticeable difference equate to lost productivity in the browser?
Given that most people launch their browser exactly once per day, when they start their system up, I'd argue not really.
What does make a difference in productivity, is usable screen space and extensions.
For usable screen space:
Chrome wins again, but not by as much as you might think. Because Firefox is so customizable, I've condensed all buttons, menus, the address bar, and the search bar, into one bar at the top of my browser, with tabs directly below. It's very usable and sleek. I have left the status bar at the bottom of the page because the info it contains about routing (if you're paying attention), and also because it contains the server spy info (an add-on, look it up), and some other useful info sent there from other add ons.
The top of Chrome is actually fairly fat. With the bookmarks bar open, it's actually 21 pixels wider than the way I have Firefox set. With the bookmarks bar close on Chrome, it's 6 pixels slimmer.
The status bar at the bottom of Firefox (which if you don't use it, you can get rid of) costs me 27 pixels, compared to Chrome.
So, let's add that up. Worst case, with Firefox displaying all the info I want (status bar and all), and Chrome trimmed right down, Chrome gets me 33 pixels of viewable screen height. About 2 lines of text.
If I get rid of the status bar in FireFox, I'm out 6 pixels of viewable screen height.
If I trim Firefox right down and leave the bookmarks bar open on Chrome, all of the sudden I get 21 pixels of screen height in FireFox's favour
(If you don't believe me, IM me, and I'll make the screen caps I based this on available).
On a 1920x1200, 27" monitor, guess how much 33 pixels difference means to mean? Very close to bupkus. My laptop has a paltry 1680x1050 resolution. Those 33 pixels don't make much difference to me there either.
So far, Chrome wins on speed (to a degree that I don't care about), and screen footprint (again, only barely).
But then we move to extensions...
And no other browser out there can even come close to the extensions available for FireFox. Chrome is almost there, largely by creating a framework that makes it simple to convert FireFox plugins into Chrome plugins. But the depth of the community and available extensions just isn't there yet.
And day to day, it's those extensions that make my life easier, and more productive.
So, long story short, I'll stick with FF for now. If they can make the UI a bit slicker, and the underlying engine snappier, that would be great. But at the moment, no browser has a big enough lead in these two departments to drive me to change.
It's not like it was 5 years ago, when Netscape and IE were both such fat pigs in need of getting skewered. No, the browser market has evolved to the point where the differences in speed and UI are so small, across the board, that the real difference is in the productivity aspects.