Forgot to mention: the new J-model has 40% greater range, 21% higher maximum speed, and 41% shorter take-off distance than the earlier E/H models.
And they even figured out how to make a tanker version that can provide ground support with a 30mm cannon, Hellfires, and laser/GPS guided munitions. Talk about loiter time.
Like nuclear submarines. The limiting factor would be the food supply. Or maybe TBMO...