One thing I'll say besides all the obvious assets he has, is that there is a mental strength to him that I think will be missed. He is one of the few players you can rely on when City aren't at it to never go missing and even if he's not at the top of his own game, he'll normally offer something to help the team when it's needed. When some players are off it, they are really off it and become passengers.
Yes match winning goals would be nice but football is much deeper than that. Take the FA cup defeat, nobody was at it, Sterling and Grealish looked lost and offered no relief to those behind them. Their heads dropped, which happens to a lot of players in fairness but Jesus' never did. He was the only forward who performed that day(until Mahrez came on), it probably would have been worse without him there. I guess I'm saying, he's one of the players you'd want on the pitch if the team are in the trenches.
I would keep him given the choice but if he wants to go, there is nothing to say.