One difference I saw
was that they remained stationary a couple of dozen feet (not sure scale is hard to judge) off the ground just before landing.
I know if I were testing one of these, one thing I would want to test is the amount of thrust required to hover and how stable that thrust was.
Simulations are all well and good but you want to match up the simulations to real life.
Also, if anything was not perfect the first time, as Andy says, you would retest until nothing went wrong before moving to higher tests.
(
My Name was saying these words inside your head on, Sat 5 Sep 2020, 10:14,
Reply)