I finally got a day with temps just right to do a test flight of h520e. Glad they took their time on this one. results are much better than expected. new gimbal make the difference. no return to land errors at all. also with eom antennas flew further from ground station that first gen h520. the flight time with oem batteries over 28 min each. distances hit over 4000ft out with oem antennas. area that always triggered rtl did not trigger with this unit. I would like to see what 4 hawks antennas will do with this unit. 390ft above the ground. this unit had a surprise for me when taking off from launch point the landing gear goes up on it's own. also if the landing gear is down when you switch flight modes in the air. the landing gear goes up on it's own. improvement made new gimbal camera does not shake when calibrations are done. the h520e is also holds well in hover. have not tested rtl landing accuracy yet. however st16s battery life gets depleted fast when recording. one flight battery at 100 percent dropped the st16s battery from 100 to 61 percent in one flight. so ratio of flight battery to st16s battery dropped from 3 to 1 st16s battery 2 to 1 st16s battery.