PN,
I agree that it was a statement of intent - I am not so keen to call it capability.
I believe it was a great effort and anything that could have been thrown at the enemy should have been.
That being said I don't think it demonstrated an ability to strike the mainland in strength.
So for me the jury remains out on the effect. Were the Argentinians so scared of our ability to get a single bomber that far that they significantly changed the game plan?