Some notes on the F787 flight.
The empty operational aircraft is something like 277,000 lb. This may have been a green bird, without interior/seats/galleys/loos, etc, which is a lot. Fuel load would have been minimal, so let's assume fuel weight is equal to the stuff which is not installed in a green aircraft.
Total thrust is 2 X 71,000 lbs. A pound of thrust is sort of like a horsepower, as the relation depends on speed.and a whole bunch of other variables.
So, approximately, you have about half a horsepower to every pound of aircraft - just like a formula one car.
So it can't fly sustained vertical, like a F16, (which has more thrusties than poundies) but is really rather sporty.
Weight & balance calculations needed to be hand manipulated to account for the extra weight of the pilot's brass balls.
Finally, although true vertical flight didn't happen, clever positioning of the camera craft made it look that way.
Magic video, even though you now know the tricks behind it.
Verum audaces non gerunt indusia alba. - Ipsi dixit MCMLXXII