If you've loaded OS 4.5 on your device give the BB browser another shot. It's not earth-shattering but it does appear to render some sites better IMO.

However, again, if you're wondering about Opera Mini then just give it a shot. There's no reason not to. It's free. You can remove it if you don't like it or don't see the point. You don't rely on others to test drive cars for you when shopping for cars, right? Why would you do the same for a browser?