The general impression among our forum gerbils seems to be that the new browser is faster than its predecessor, although some don't like a few of the changes brought by the new release. That's not to say those changes can't be reversed, though. For instance, gerbil Crazybus discovered that browsing to about:config and setting browser.tabs.closeButtons to "3" gets rid of the individual close buttons on every tab, and that setting browser.urlbar.hideGoButton to "true" removes the "Go" button that's now embedded into the location bar.
Do you have any other tips to share? Or do you need a hand to tweak the browser to your liking? Even if you'd just like to share your impressions, feel free to register a forum account and join the discussion.