I use the stock BB browser and OpreaMini. I'm still getting used to opera since i just got it a few days ago, but so far it seems to be faster, i just need to get used to the slightly different layout.
I use the BB Browser and Opera Mini. Some say Opera loads quicker, but I honestly can't notice a difference. To me, most web pages look and navigate better on Opera, but there's still a couple that work better with the native browser. Also, my online banking doesn't work with Opera. I tried Bolt for a week, and just couldn't get used to the navigation.
I use Blackberry and Opera browser. One neat thing about Opera you can synchronize Opera on your PC with Opera on the Blackberry and they synchronize over the internet. You can have access to your favorites from Opera on PC on the Blackberry.
Doc
I mainly use the Opera Mini browser because it is faster and I just like the layout better, but sometime you'll need to use the BB browser to download programs. Bolt is ok, still needs a little work in my opinion.