Hmmm, I've tried Opera on my iPhone... Not sure what the advantages are over the built in browser... I can't really read the text
I'd stick with a webkit based browser, regardless of platform.
Well, to be fair the Opera you would have tried on the iPhone is Opera Mini v5 and the one JJ is talking about is Opera Mobile 10.
Mini VS Mobile
Opera Mini is a more of a web "viewer" than a browser. When you call up Amiga.org, Opera Mini requests it from the Opera severs which load it, format it, compress it (probably why you get blurry text), and then send this "image" to your phone. It's much more static. There are no animations or flash.
Opera Mobile 10 that JJ is talking about isn't available for the iPhone(sadly) and is a full web browser. It has flash support and renders pages itself, etc.
OperaMini (what the iPhone has) is a pretty cool app to have if you are on a slow network. It's also great if you are on a non-pda type cell phone as it is usually 10x better than what most 'standard' phones come with.
Opera Mobile though is in a whole different class than Opera Mini. I'd love to see it on iPhone someday.