Some of the UI is interesting (though Mozilla has had the "Revolutionary new Bookmarks filing scheme" for around a year now. But as a render it sucks. The speed is great, but I'm seeing multiple pages where stylesheets are ignored, visual errors and error message dialogs. Some of this will be fixed by 1.0 but its got a long way to go to catch up with Chimera/Gecko as a renderer. Speed is nice, but Chimera is plenty fast enough. Pleasant, but far from something I'd switch to. So far.