you are referring to a later post where the value is estimated as 90megawatt for 10 minutes .... exactly the point I was making! not that i agree with that estimation, the get off the ground value will be significantly greater than the climb away value.
But there are several other possible gains
1 fan speed can be optimum without gears
2 contra rotating fans also can be achieved very simply without gears
3 and finally for getting off the ground "ludicrous" amount of power available for short bursts and this power is instantly available without any turbine lag which is a good thing for a go around.