As with another user below, I have all the current browsers for the Mac, and used to rave about Firefox. I'd always stayed away from Opera after trying it when it was a 'paid for' app.
A couple of months ago I downloaded it from VT pro, and all my other browsers have been consigned to the trash. It's fast, (especially the downloads - check it out for the DL manager alone), intuitive, and elegant.
And it's rock steady.
The only scarey thing is that Version Tracker doesn't recognise that it is installed on my Mac. What's all that about?