The Brazil goalkeeper has just left City for Fenerbahce - just as Gigio Donnarumma arrived from PSG.
On Ederson, Weaver told the Manchester Evening News: "He's almost changed the face of goalkeeping. He was one of the first goalkeepers who really put the ball at risk.
"I think he's been a phenomenal keeper, the most successful in the club's history. What he's achieved and what he's won is unparalleled."
Weaver also said: "It's like goalkeeping on the edge with his starting position, the way he receives it. One of the biggest things that I see in him, it's not the confidence he's got in himself, it's the confidence that everyone else has in him because they'll give him the ball almost on his goal line under pressure and it's just not an issue.
"He'll always find the right pass, and you can almost count on one hand how many times he has given the ball away in a dangerous position in eight years. His short game has been absolutely pinpoint and precise, and then we've seen on various occasions his long game as well.
"He can easily hit a 70-yard diagonal straight over the full back into the path of the winger or wide man or straight through for the likes of Haaland or Aguero. Those sorts of attributes with his feet, I don't think I've ever seen anyone quite as good as him."