This morning I tried to "do" KP2 in Overture. The setup went very smooth. No problems at all. Before I setup the Overture-piece with KP1 and all CC#'s normally used for volume, timbre, lenght, portamento, etc. Now I played the whole piece with KP2 and to my surprise the whole lot was distorted (too loud).
Next I re-assigned CC#1 and dragged it to the ModWheel to get that KP1 idea again. It still sounded distorted, almost everything went into the "red" zone. All other re-assignments of CC# values didn't give me back that so carefully configured soundbalance using KP1. I spent three hours doing and trying that.
I got the impression that in KP2 volume levels are configured different than in KP1. By the way when I assigned CC#1 to the ModWheel it was impossible to vertical scroll thru that Auto/Midi window and the Red-arrow was lit continuously. Until somebody at NI or Garritan writes a tutorial how to employ this nice looking KP2, I continue using KP1.
In spite of the help of all esteemed forum members, I decided not to use KP2 until that tutorial. I feel like one those guys who needs "KP2 for Dummies".