Firefox 3.0 Beta 2 shows promise on the Mac.

From my testing so far, Firefox 3.0 for the Mac platform seems to be a keeper. The first thing you notice when you fire it up is the speed that it renders webpages. I believe they revamped the Gecko engine on the 3.0 release. Another standout feature is that the UI (with the Proto theme) is unbelievably 'Mac like'. Unlike 2.0, Firefox 3.0 just 'feels' right now. That being said, I have not had a lot of hours on the new beta release yet, but it appears stable and solid. On many of my frequently visited web pages the text rendering was noticeably improved, almost on par with Safari. There is smooth scrolling which is an asset when browsing text heavy web pages. My StumbleUpon add-on and Adblock Plus seemed to survive the upgrade, but understandably, the other devs have not caught up with their add-ons. Overall, I am very impressed with the hours of work that must have gone in to the 3.0 release. For early adopters it is definitely recommended.