Mancini ended the 35 year drought (and the 44 year title drought), and has earned his place in our history. He will never be forgotten. As a people person, though, he seems (repeat for the hard of hearing, SEEMS*) to have left a bit to be desired. IIRC quite a few of the behind the scenes staff at the club (chefs, laundry, groundstaff etc) were not broken hearted to see him go. I suppose the old saying about breaking eggs to make omelettes comes to mind.
*I said "seems" as I wasn't around the club at the time and can't verify how he was as a person away from the media.