In my opinion, Firefox 3 is an overall huge improvemnt over 2.x. Memory usage is lower, ive noticed a big difference in page rendering speed, its more secure and the new default theme looks more stylish. The Awesome Bar is a nice addition as you can tag your bookmarks, and as you type those tags in, the awesome bar will suggest matches. It just adds to the HUGE customizability that Firefox has. The installation goes right over FF2 which makes things even easier. So, in a nutshell, i suggest you get FF3.