I'm confused. Currently gliders under discussion are Discus, Discus 2, Ventus and Ventus 2 (all with various sub-models). Original poster first questioned differences between Discus (std. class ship made in 80's) and Ventus 2 (15m class from nineties. In next post he talks about Discus 2 (std. class ship made in 2000's). So exactly what two gliders are we comparing?