I've heard the gear ratio was changed to a much higher one, slightly different wind motors were installed and a larger prop is on it now. 36X15 instead of the "little" 30X12 . Much higher thrust, only about 2mph less pitch speed (irrelevant), and about 10% less power being consumed from the batteries,.. basically just a lot more efficient. It's great what you can do with gearing and propping,.. almost magical,.. less power going in and more coming out simply due to much increased efficiency of a larger prop. Since it was turning the 30X12 the same revs as a DA150 before, it's actually higher performance than gas now, and less input power.