The Ventus b is about 96% and the Ventus C is about 98% of the Ventus 2. They are very similar in the run, the V2 climbs better. The difference in the Ventus b versus c was mostly in the wing root that allowed the c to have less drag and climb better. The biggest difference from the V1 to V2 was improved handling at low speed and a softer wing that allows a better feel for the air. It is highly recommended that all V1’s have winglets installed if it has not been done yet. I also found winglets on the 16.6 and 17.6 tips improved the handling when flown with the extensions.