Iceriderwrote a review of Marker Duke Ski Binding on April 24, 2009
If you only (or mostly) consider the downhill aspect, the Duke (and I'm assuming the Baron as well) easily beats the Fritschi Freerides. I swapped out my Freerides with Dukes on a pair of skis and the improvement in control and power transmission was huge.
However, if taking into account the touring part, things get more mixed. In addition to having to take off your skis when going from touring to skiing (and back), the Duke's risers are much more limited and finicky to adjust vs. Freedrides. Also, as others have mentioned, there's a tendency for ice to build up in the Dukes making it hard to convert from touring to ski mode. I once accidentally bent the (somewhat wimpy) metal piece that slides the binding between settings. Got a warranty replacement but now I always use my poletip (or some other tool) to scrape out any snow/ice that hinders free movement.
Also, I can second that you'll need to increase your DIN by 1 or 2. Don't know why but these bindings release easier than standard alpine bindings.