The JS1 and ASH26 I used to fly were noticeably more roomy around the shoulders and upper arms than the V3M and I would be amazed if the JS2 wasn't similar. The Ventus Performance fuselage has a vertical side wall for a few inches below the cockpit rim whereas the JS gliders follow the Schleicher concept of a reinforcing inward curvature of the cockpit rim beneath which the shoulder and elbow-moving space is quite roomy. I wouldn't reject the JS2 on cockpit size alone without sitting in it first. Oscar Goudrian fits according to the picture on the JS FB page.