When it first came out, I decided to keep using verion 1.5, and see what happened with other people before using version 2 myself. Now it's been out for a while, it's had a minor upgrade, and it's getting good reviews, so I'm giving it a whirl.
It's been a nice suprise, as it has many small but useful features. Here is a link to a review that goes over some of those features:
Firefox 2.0: Subtle Changes, Big Difference
Most of the new features in Mozilla's Firefox 2.0 aren't readily apparent, even to a seasoned Firefox aficionado. Once a user digs a little deeper, however, the new tools and capabilities become more obvious. Phishing protection automatically investigates suspect e-mail, an enhanced search tool suggests additional terms and Session Restore can save the user after a crash. [...]
As a blogger, I've really gotten into using tabbing. Tabs are so much easier than having multiple windows open, it's been a real time saver. This latest version of Firefox has even managed to make the use of tabs even better!
It used to be that there was one "X" button at the right of the tabs, and you had to use it to close whichever tab was active (or in the forefront). Now each tab has it's own "X" button, and you can close it without having it in the forefront.
If you accidentally close a tab, you can easily bring it back by finding and selecting it under "history".
There are many more useful features. You can download Firefox 2 here:
Firefox 2 - Rediscover the web.
The page this link goes to also has three links on it, labeled "Enjoy a Better Web Experience", "Enjoy a Better Web Experience" and "Personalize Your Browser". Each will tell you a lot more about the features version 2 offers.
Firefox 2 is free to download and use, and is available for Windows, Mac and Linux operating systems. Check it out, I think you'll be glad you did.