Yes, I have skied both. Which is better depends upon the skier. The current AC-4 is relatively soft torsionally (esp. for a Volkl) and has a light nimble feel. Some Volkl purists scoff at the current model as being something less than a "real" Volkl as it is perhaps a bit too easy....
: Personally, I disagree with this view as I think that Volkl has done a nice job of making their skis more skiable for more people.
However, for those purists, next year's Volkl lineup in much closer to the "old" skis and as such, while more powerful, are not as user friendly for some.