He had two advantages over Chesley Sullenberger: He was already on the way to landing, - that is higher airspeed, prepped to land - and with a shitload of altitude to spend for airspeed on the way down.

And secondly he didn't have to get down in a densely populated area with barely enough space for a goddamn car to ride, much less of a Boeing to land without breaking the wings off.

Sully's miracle was not to land a jet without engines - that has indeed been accomplished before: the Gimli Glider did that too, on what once was actually a runway, the Galunggung Sailing club survived ingestion of volcanic ashe and a subsequent flame out on all four engines, more recently Cathay Pacific made it safely down with one engine idle and one in flight (serious overspeed landing).
Sully's miracle was to demonstrate it was actually possible to land a jet on water, something that usually costs a lot of lives, if not every soul on board.

So, while there's absolutely no reason to talk down what Dárdano did when both his engines failed due to the heavy ingestion of water they went through, it is not entirely comparable to what Sullenberger did on the Hudson.

Mind you I think the most hilarious part is how they got the plane of the dam afterwards: With a new engine and just enough fuel to make it to the nearest airport they actually took off from there again…