I'm honestly happy that he went to Chelsea rather than any of our other Premier League competitors.
They are the ones who currently have the most talented/complete set of midfielders to play either in a midfield two or three compared to the likes of City, Arsenal, Spurs or Liverpool. Lets assume that they've brought him in to replace Matic or Fabregas, who both have shown vast amounts of talent bar the freak season last year. If they are to replace Matic, who'd I argue had a better 14/15 season that Kantes 15/16 season, I would be happy. If they replaced Fabregas, who was one of the main reasons Chelsea won the title that year, I would not be unhappy (for a lack of a better word).
Compare that to him replacing either one of Coquelin, Cazorla (?), Wilshere, Eleny (?), Henderson, Lucas, Can, Fernando, Fernanindho, Delph or Toure?
He's certainly a good player who had an insane season with Leicester, but the fact that Chelsea was the one to buy him is not as worrying to me as if any of the others got him.