Aquilani has been really poor for Pool. He was never first choice for Roma, instead he was always a substitute to D.Pizarro. What exactly has Aquilani shown to prove that he could have been one of the best?
I'm not saying Gago is better mind you, he hasn't proven much either. I was just surprised by the comment, "he would have been one of the worlds best".
As for the comparison between the two. I don't think they play the same role anyway. Gago is more of a player that would sit back and distribute the ball from deep. I'd say he's more of a deep lying playmaker. He can tackle well, and he has an extremely high work rate, which he rarely gets credit for, plus his ability to pass the ball and his intelligence too. Aquilani is more of an attacking CM, he's the more creative of the two, and he has the ability to shoot too. I think they are two different players personally.