Exclusive Features (Pros)
1. Opera has always been one among the most stable, fastest and light-weight web browsers.
2. Opera Turbo is one among it's most powerful tools, which is so much helpful for users with slow internet connections to browse the web faster than any other browser. I have found it to be the best browser while using a dial-up connection.
3. Opera comes with many essential features built-in, which usually come only as add-ons (and some features don't even come as add-ons) for other browsers like Internet Explorer and Mozilla Firefox.
4. With Opera Unite, you can host a web server to share files and stream media.
5. Opera's Speed-dial is another pleasant feature that stands out.
6. Opera seems to be faster in handling scripts than any other browser. It deepened it's roots in script management significantly, from the launch of the Alpha version of Opera 10.
Drawbacks (Cons)
1. Opera widgets are not so useful, when compared to the Chrome and Firefox add-ons.
2. There are some websites or forms or scripts which are compatible only with IE. So, if you are a frequent user of such websites, you might not be able to completely rely on Opera. But now-a-days, it is a rare scenario.
What's New In Opera 10.51
1. Opera has replaced it's old Javascript engine with a new one called Carakan.
2. New user interface that blends excellently with Windows 7.
3. The latest version, Opera 10.51 fixed the issues with scrolling.
4. Widgets are now able to run independently, off the browser, on the desktop.
5. The latest version has introduced HTML5 video support.
Download Link: http://www.opera.com/download/