Opera recently unleashed the public beta of their newest Opera Mobile 10 for Symbian Series 60 platform. It features the same user interface as Opera Mini 5 beta including tabbed browsing and a speed dial similar to their desktop edition.
It is quite a bit faster than Opera Mini 5 and the built-in Webkit browser. Unfortunately it is a RAM hog (about 20MB used with a single tab open). With Opera Mini 5, I can run Gravity, the standard S60 browser and a couple of other applications in the background at the same time, even with the limited 45MB of available RAM on my Nokia E55. Not so with Mobile 10, as eventually after opening a couple of tabs I will encounter the low memory message. It also does not have support for flash, though I am not sure if that is a good or bad thing.
Overall, a good first impression. The rendering is quick and accurate offering a truly desktop like experience - not surprising as it uses the same Opera Presto web layout engine as their desktop browser. You can even tinker with the settings via about:config. For example if you have a device with more RAM, you can always increase the cache size for better performance. I like it, but personally I see no major benefits for users to completely switch over from Opera Mini 5/Series 60 web browser combo just yet, particularly if the lack of available RAM is an issue.
Opera Mobile 10 beta is compatible with any modern devices running on the Symbian Series 60 3rd/5th edition and Symbian^1 platform. These includes the Nokia N97, Samsung Omnia HD and Sony Ericsson Satio. Access the beta by directing your mobile's standard browser to http://m.opera.com/mobile or download here.
Update: Opera Mobile 10 beta is now also available for the Windows Mobile platform.