Okay, I've only been using it for a couple of days. I have to say very cool. I hope it's released "Real Soon Now!"
I went to the Moz forum to pointed to. Pages worked pretty good, I didn't notice anything odd except on one. The CSS drop down menus was it, they didn't pop down in the right spot. I though that concept was very nice, much better than the javascript menus.
Looking at the topics in the Moz forums and the Opera forums, there seem to be what I consider an odd rivalry. Basically, it's not who's browser has more bell and whistle features or better skin, but who is more standards compliant and what pages really show this off. I though that was astoundingly wonderful. Mainly, it looked to be revolving around cutting edge CSS, which both handle nicely except for their own little faults. Both side seem to have a hard time finding pages that work perfectly in their browser and not in the other( no matter how small the issue may be).
Of all the CSS examples they threw at each other, even the ones that were just alittle off on one of the browsers, all were mangled by IE (the "Superior" browser).