He's a great manager plain and simple, evident enough by overjoyous posters in this very thread at the announcement of the news. Not on Fergie and Pep level, but certainly ahead of Wenger for me. Probably ahead of Mourinho too, simply because of the attacking style of football he employs. Unlucky not to have more titles, as some of the 2nd place points totals they racked was enough to win leagues by large margins, absurd they came 2nd, not that any of us would complain.
He's done a poor rebuild job though, and with Salah and Van Dijk getting on now, that team is bereft of quality they had during their best spell under him. Even though they pushed into title race this late in the season, they're not a player or two away from winning it next year, he's got them punching above weight this season and it's going to show next season.