Mark, I am glad you have an interest in the Xenos wing. I really like mine. I understand the airfoil is by the late F.X. Wortman, aeronautics professor at U of Stuttgart. The chord of the Xenos wing is much shorter than the regular Sonex (I remember 4"??). BUT most important is to remember the rest of the Xenos fuselage is NOT like the Sonex in several critical points. I have come to really like the Video by Jeremy Monnett found at
http://www.sonexaircraft.com/aircraft/xenos.html . Notice especially what he says near the beginning about the fuselage length (more leverage) and the larger tail surfaces. "horses for courses" he says. Sonex is a great little "fighter plane". Xenos is a great soaring gentle giant. If I could, I would own one of each (actually a Onex would be great.) But I wait patiently for the e initiative to produce the plug n play electric propulsion for my present Xenos :-)
PS also our Xenos wing is the only one of the present Sonex group with a fixed trailing edge (no flaps)