Sorry Cat, don't mean to hijack your thread. But, anyone try google chrome?
Yes. In terms of rendering speed, it is considerably faster than Firefox. I didn't mind the UI, it was easy to use. However, what I did mind was the fact that it doesn't support non-Intel Macs or ones with Tiger (OS X 10.4). I can run it on a 10-year-old PC but not on a 5-year-old Mac? No thanks.
I stopped using FF for a while, because the earlier versions of 3.x had some serious issues with sluggish performance and sudden crashes. I used 2.x until my add-ons no longer supported it, and then used Chrome until Mozilla got their shit together. As of 3.6.4 it's been working fine for me. I'm probably not going to update it for a while unless my add-ons require me to, or some great feature or security patch comes along.
I've tried Opera, and it wasn't bad. It supports PPC Macs and Tiger, and also has a version for Linux, so that's a big thumbs-up in my book. It also has some extremely cool built-in features that I'd like to see other browsers emulate, although I could never get the sidebar configured quite the way I would have liked. Unfortunately, I've tried two different versions of Opera, and they both suffered from slow page rendering (slower than Chrome, anyway) and they both also experienced crashes.
Firefox works well for me and here's why: Firefox Sync. I can open up tabs and add bookmarks on my Windows machine, and switch over to my Mac Mini, or my Linux machine, and refresh the sync with the press of a button (or wait for it to do it automatically) - bookmarks, open tabs, history, site logins, etc...it's all kept synchronized. Hell, I can visit my father-in-law, add the add-on to FF on his Mac, log into Sync, and all my stuff is there...then log out of Sync when I leave so my porn links aren't there for him to see.
No more saving bookmarks.html every time I want to reformat something. I want this on all my systems, which is why cross-platform support is important to me. Until Safari and IE start supporting Linux and OS X, they can kiss it.