It rocks the BB Browser in speed. I love the native browser's navigation, but it's just so ******* slow for anything with any actual content. Try loading the regular crackberry.com site in the BB Browser and see how long it takes.
Opera Mini is really not that hard to navigate with. You have to hit 'show keyboard to type in the address - big deal. It doesn't lag when you try and type in forums also (like here).
Speed>all. I don't feel like sitting there forever.
there are several threads that go into details on the bugs, issues. i would recommend searching for one of them which will give you a huge wealth of info on opera mini