He seems like a very good time-trialer and put in an amazing performance this Giro. I think it was rather exceptional in a way that he went beyond what would normally be possible for him, much like Voeckler when he held the Maillot Jaune for a week. He also seems like a genuinely nice guy!
Plus I think no one has mentioned that he became the leader of his team, so he had guys like C.A. Sorensen and Gustav Larsson working for him in the mountains. The white jersey and the top-10 is a team effort, everybody contributed to help Porte as much as they could, so that he could be as fresh as possible towards the end of the stages. I think that's the whole difference to Kiserlovski - he didn't have a team working for him, he had to work for others.
Anyways great success though by a young Saxo squad, I think no one expected them to do so well!