I tested about 80 models of skis last year in the course of deciding the best 45 or so to carry in my store. I think that those two have a very different feel. The Volkl is stiffer longitudinally, but softer torsionally and has a decidedly lighter feel. In the heaviest broken up crud, the AC can get knocked around a little. The TF is a powerhouse all the way and blasts the crud better but takes some serious commitment by the skier.
I think that the choice boils down to snow type and style. If you ski heavier crud often and like to charge hard, the TF may have the edge. OTH the AC is a little easier going.