An interesting, unbiased test of browsers on multiple platforms.
Some interesting finds in these tests:
Firefox is NOT faster than IE, as it claims (although with all the security flaws and non-support of web standards found in IE, Firefox is still the better choice).
Opera, a favorite of my dads probably since version 1, is the fastest browser overall on all platforms, Linux, Windows, and Mac.
If you look at the graphs for Windows browsers, Opera is at the top of every test.

Using Opera 7.54 on Windows XP
I’m not surprised. I think because Opera has a good caching program. I’m still using Opera as my first Web browser, and Firefox when I have to do Wells Fargo online (I’ll be switching banks soon).
In addition to its speed, Opera still has many features that are not in Firefox, or are better than Firefox. Firefox’s download manager, for instance, is years behind Opera’s. Opera can remember all the tabs you had the last time you had it open, and it can also automatically open new tabs by clicking on the bookmarks once. Opera’s Windows are resizable.
The most annoying thing about Firefox is when I loaded one of the extensions, the URL address bar disappeared, and I can’t get it back after a couple of reinstalls.
Using Opera 7.54 on Windows XP
I forgot to say that even with its deficiencies when compared to Opera, Firefox is ages ahead of IE.
Using Mozilla Firefox 1.0 on Windows XP
If you ever have the url address bar dissappear again, try opening a new window (Ctrl-N), and that should reload a fresh new window with all the toolbars intact. I had this same problem after I installed the “remember last window” extension (I forgot what it’s really called). Certain web pages are opened with javascript stating certain attributes for that window–like no toolbars, so this wasn’t a Firefox problem.
The flexibility of the extensions in Firefox is definitely a good feature–however, they are created by people outside of mozilla, so they can be less than quality. But, one of the reasons why Firefox is so popular is because it’s open for others to develop extensions and such.
Using Mozilla Firefox 1.0 on Windows XP
I do want to add that I agree that Opera doesn’t get the respect that it deserves. But one of the reasons web designers don’t like Opera as much as Firefox is that Opera sometimes renders web pages differently that what you would expect. It’s not as bad as IE, but sometimes unpredictable.
Using Mozilla 1.7.5 on Debian GNU/Linux
Opera doesn’t get respect because it’s not free. Period. There is no market for a browser you have to pay for.
A fresh install of IE may be faster than Firefox, but I’m willing to bet that the AVERAGE IE installation is much slower due to spyware.
Using Mozilla Firefox 1.0 on Windows XP
Heh, good point Phil.