Firefox 3 beta 2 includes some subtle usability improvements in the new Download Manager, which now displays the domain of the site from which the file originated next to each entry. Mozilla also improved its Places bookmarking and history system which is a major new feature of the Firefox 3 browser. While the new Firefox visual styles for Windows and Mac OS X haven't landed yet, this beta is the first to include the native GTK theme for Firefox’s default icons, buttons, and menu styles in Linux.
Even with a few bugs here and there the speed improvement in Firefox 3 is noticeable when compared to Firefox 2, and I for one have had no problems with it crashing. You can check Mozilla’s “what’s new” page for Firefox to read through a list of improvements and fixes in the latest beta, which is available for download here.