Firefox also automatically, at your option, imports from Internet Explorer a host of settings, including Internet options, Web site favorites, browser history, saved passwords, saved form information, and cookies. Saying that doesn't really get across what it means; what it means to anyone who was using Internet Explorer regularly prior to Firefox's installation is that you can pick up where you left off in IE using Firefox henceforth. About the only thing you'll probably have to clean up is Bookmarks and the Links bar/Bookmark Folder bar, if you used that in IE.
People have picked on Firefox because Java and Flash, as well as possibly some other plug-ins you might be using, aren't automatically carried over to Firefox. A previously installed version of Acrobat carries over automatically (well, version 5.0 did, anyway). There may be issues in this area that I haven't discovered, but the plug-ins thing seems minor to me.
Cons: When Firefox is installed on a Windows XP (and presumably Win2000) machine that has multiple users configured for people sharing a single a computer, Firefox's installation routine doesn't stop to ask you whether you want the program installed for all users or just the current one. It installs it for all users. That's unfortunate because if one of the other users decides to uninstall the program in their login, that program will disappear from all users. If two people are sharing a computer, and only one wants Firefox installed, that's not possible the way Firefox installs now. Other programs that are more Windows-aware handle this by asking you whether you want to install a program for one user or all the users. This is something that Mozilla needs to fix, and soon.
I love the IE importation features, but I wish that Mozilla had allowed us to specify from what machine we want to import IE settings, favorites, and saved data. The routine can only take that information from the machine you're installing from. It would save me tons of time if I could tell the important routine to get all that information from a different machine on my network.
Options and the Rest
Speaking of help, the built-in documentation has pluses and minuses. The basic Firefox Help file is well designed and fairly well stocked with information. The Mozilla Firebird Support site adds many additional tidbits. There's also a Help file aimed specifically at Internet Explorer users (which reminds me a lot of Word 6.0's inclusion of Help for WordPerfect users). Be sure to check out the Firefox Keyboard Shortcuts and Mouse Shortcuts support pages.
The downside to Firefox's help facility is that unlike Internet Explorer and most every app Microsoft writes these days, there's no context-sensitive help. To access this in Microsoft software, click the question-mark icon in the upper right corner and then click it on anything in a program you don't understand.