badly aged
As some other stated it is one of the not so good Hitchcock Movies. Actually may be it was better some 40-50 years ago. He plays an repulsive male Chauvinist while the Marnie Character is often overacting and is also not a loving character so you cant really root for anybody here.
It is far too long and the music is kind of a medley from Vertigo and also sounds very repetitive.
Nevertheless I also enjoyed the Hitchcock style of the Movie. Not as much as in "Dial M for Murder" or "Rope" but it was still there.