I have been really happy with the new FireFox. I have however noticed some small rendering differences between FF2 and FF3. That means more testing. At first it was a pain to have to test for both of these browsers and then I ran into MultiFireFox. It lets me run FF2 and FF3 side by side so I can quickly and easily preview a website in each. Wonderful! This version looks to be only for the Mac, but for you PC users you could check this out.