Opera 12 offers a lot more eye candy and extra fun, as well as useful tweaks. You can now apply one of hundreds of themes to customize the look of the browser and surf in confidence knowing that even if a plug-in crashes, Opera won't.
The themes work just the way they do for Chrome and Firefox browsers. In Opera, go to > Appearance...and then browse for a theme to apply.
Lots of other extra come with the upgrade, including running plug-ins in a separate process, faster page loading and rendering, 64-bit Windows and Mac support, and supports for more languages. If Opera 12 is still not fast enough for you, you can try experimental hardware acceleration.