Avant isn't new... its been around for the past 2 years now
Firefox > AvantBrowser.
...Of course, this is my own opinion.
But remember, Opera's been doing ALL of that for the past 3 years.
There aren't any real advantages of Avant over Firefox... Firefox actually conforms to W3C Spec, and that's all I ever need. Avant is insecure by virtue of using the Trident engine (okay... its more secure now than it *was*, but still isn't as secure as Firefox,
either by design or obscurity)