It took a bit of hacking of install.rdf files to find out which extensions really didn't work and which just said they didn't work* but I'm now running Firefox 3 Beta 2 as my browser under Fedora. So far my opinion is mixed, especially after I heard about one of their changes post-Beta 2, but mainly good.

Firefox 3 introduces what they've called the almighty bar. Basically it's a location bar on steroids after a bad case of interface re-writing. More of my thoughts on it are here. If it wasn't bad enough that ?sl? doesn't list slashdot.org as the first result any more then it is also big, attention grabbing and intrusive. On top of that they've apparently removed the option to revert back to the simpler rendering (if not the original auto-complete-instead-of-searching-everything-and-the-kitchen-sink behaviour)

On the plus side the rendering has improved (it now passes Acid2 as an arbitrary CSS test) and it is apparently much leaner, faster and less memory hungry then Firefox 2 (it is currently using about 64MB of 1GB after an hour of browsing - never actually checked previous versions).

Other things I like are the quick bookmark icon and (for some reason) the inclusion of the favicon on a little button. I guess it makes it easier to see that you can do something with it (although why they hid the site security details behind it I don't know). I don't tend to use the downloads manager too much, but the improvements they're supposed to have put in there sound good (searching, resuming, information including where you downloaded it from after you've finished downloading). The overhaul of the bookmarks also seems to provide more power and flexibility, but quite why they changed it to ?places? I don't know. Oh, and I like that it now uses native GTK widgets. So, is anyone else using Firefox 3 yet, and what do you think?

I've lost ColorZilla, which I hardly used, and Tab Mix Plus, which I used to reset a couple of bits of behaviour and that was about it. Venkman, WebDeveloper, Live Page Rank, AdBlock Plus and the British English dictionary all worked and Download Status Bar have an update on their site, but not in the addons site.