Driven mainly by the under-the-hood rendering improvements and the availability of a substantially more recent x64 build, I decided to give Firefox 3.0 another try today. Oh boy.
Compatibility problems are still running rampant throughout my Firefox 3 install. I managed to fix the some of my issues through unofficial updates, hacking around with Firefox's RDF control files, and in the case of the classic and self-preferred Googlebar, turning to underpowered alternatives. DOM Inspector isn't an optional component anymore, and I can't seem to install it directly from the "Firefox Add-Ons" page, so I assume I'm going to have to go manually install it and hope for the best. DOM Inspector is the best HTML debugger I've used, and I wouldn't particularly enjoy having to figure out Visual Studio 2005's less-equipped equivalent.
Speaking of "Firefox Add-Ons", once known as "Mozilla Update", is the site really necessary in the first place? A repository of extensions is cool, but the totalitarian stance they're taking on extension dominion through various means is somewhat disheartening. I greatly preferred the old model of the now-mostly-stagnant Mozdev, where there was a higher degree of separation between the developer and distributor, and it wasn't necessary to create an account and log in just to download an extension. Humorously enough, even "Firefox Add-Ons" can't seem to keep up with the new error-checking schemes in Firefox 3: the vast majority of extensions give me some error pertaining to the new security features.
Firefox used to have pretty good FTP support, using a clean, flat list of files and directories that could be navigated like any Web page. Now they've apparently implemented some sort of XUL-based FTP client akin to that of Netscape 6.0 and early Mozilla milestones, with the exception that it's actually less functional than the NS6/M1x model. Unfortunately I can't seem to find any pref to turn off the new interface, either.
I find the new Firefox 3 theme visually unattractive. I'd go install a better-looking one from Firefox Add-Ons, but for reasons unknown, I can't seem to do that.
Apparently, few provisions were made for those that tried upgrading to Firefox 3 early on, went back to Firefox 2, and decided to try out Firefox 3 again after adding bookmarks, saved passwords, and the like in Firefox 2. I opened Firefox 3 to find things exactly the way I'd left them... Roughly a year ago. Thankfully deleting all my SQLite bookmarks and importing my old HTML boomarks to SQLite wasn't difficult at all. I keep passwords on paper, so manually entering a couple into the new signon log isn't so difficult in my case, though may be a greater burden for someone that relies exclusively on PSM to store their passwords.
So Firefox 3.0 isn't completely terrible. It loads and runs faster than Firefox 2 did, and manages memory considerably better: I'm currently looking at around half of the usage I experienced with Firefox 2. JSBench scores are pretty good: in a comparison of Firefox 3 x64 to Firefox 2 x64 and IE8 x64, my scores were roughly 450ms, 950ms, and 1250ms, respectively. GIF rendering speed has improved slightly, especially at higher resolutions (I ran an overkill test of a 35-frame 800x600 image set to render at 5fps).
For the past few years, I've been watching the development of KDE and Konqueror from a distance, and to be honest, I'd rather use the recently-released Konqueror 4 than Firefox 3. Over the summer, I'm going to try out openSuSE Linux again, and see if I can get used to using it full-time.