I have flown lots of bipes; 7 Aeromasters, 2 Phaeton40's, two Phaeton 90's, 3 Lazy Aces, and ALL required that the upper wing be 1.0 to 2 degrees more negative than the lower wing in order to fly decently. It is surprising what a small amount of change in that upper wing incidence will make on the way the plane flys. If possible, set the upper wing up so that you can easily make minor changes so you can get it tuned to your liking, there will be one spot much more enjoyable than the others. Each plane will be slightly different, even if built from the same plans.