So I rode both, back to back today. I rode the Priller first, and in the interest of full disclosure I'm going to say that it has BRAND new tires, so I took it easy at anything other than full upright.
It has a FANTASTIC chassis, it feels like its up on its toes, ready to sprint in any direction you nudge it toward. Not at planted feeling as the Duke, but again, read the tire comment.
The engine. Honestly, at this early juncture, it let me down. I thought it would be more powerful, smoother, and more modern. Across the board, I prefer the 996 engine. It REALLY makes me want to spin up a 1098. Archren? :)
I found a couple things I would like the Duke to better after riding the other Italian bike, the 4 pad Brembos are breathtakingly good for instance, and I'd like my fork to work more like the Ohlins (who wouldnt...) so I have something to shoot for after the 'Stan. Its good to want things.