Pros: Fast, good page rendering, RSS reading
Cons: Can't install Blackberry apps OTA with it
Opera Mini is a fabulous alternative Web browser for the Blackberry. It features bookmarking, RSS feed reading, and account synchronization. For example, I loaded an edition of Opera Mini on my Motorola RAZR v3xx and it was able to synchronize my bookmarks and RSS feeds so what I saw on my RAZR was the same as what I see on my Blackberry in terms of settings.
Page rendering is pretty fast, and the text is easy on the eyes.
I did find that performance increased when I turned off settings synchronization after the initial load. When pages are loaded in Opera Mini it seems to try to synchronize your settings first, then go on to load the content. Logging out of Opera's synchronization avoids this extra loading step.
There are still times on the Blackberry where you will still need to use the build-in Blackberry browser, for example loading applications over the air. Attempting to do it from within Opera will not succesfully install an application.
Opera Mini is a great free product... my only regret is that it isn't the default browser on more phones.