i see no flight changes from flex even when im doing hammer heads at full throttle, the only thing is that the tail bends slightly, but i have only seen that durring tail wages and it didnt make the plane respond any different. i fly it for about 15 minutes on a single charge. with a 10x4.7 prop, it goes verticle with no problem. you can do anything you want, hover, snap roll, whatever you want. make sure you follow the CG properly, or the plane will be an issue while trimming. also the inner canopy is weak, make sure you put something in it to make it stronger. otherwise heat up that hot glue gun. other then that. ist great, i recomend you get one.