As no-one else has answered I offer you my two-pennorth.
I would say he was not overrated. I think some of the scenes from his films are enduring masterpieces: the huge feeling of emptiness in the aircraft scene from N by NW, for example, with straight roads stretching away to infinity and a sense of total isolation; the seedy tawdriness of assignations in scruffy hotel rooms and dirty motels and the sense of threat from diving for mile after mile through the cold rain in Psycho; the imprisonment of a man with a broken leg trapped in a small hotel room with only a small window for entertainment, through which he imagines murder; the Mount Rushmore climb scene.
Of course Hitch**** overestimated his special effects in the birds, some of which simply doesn't work, but in a period where the mafia or the McCarthy/NIxon hearings frequently dictated who worked and who didn't, as well a innumerable highly vaunted actresses whose major skill was associated with the casting couch or sleeping with the studio boss, Hitch**** seems to have led a fairly ordinary life. He also largely avoided making films which were simply lies told on behalf of this pressure group or that part of governemt, which has to be a major point in his favour.