i got to fly my open b design today and i like it, lots of improvments are needed but overall i am happy, going from selig 8036 into clark y helped a lot, clark y seems to be lot more solid in the air. it is not as fast as i remember seeing some Avengers fly, how fast are average open B models fly on 64-72 inch wingspan, i am running a norvel and it turns around 17.5 k, with a can, the speeds are around 85-90 mph.