Dull and dopey. So, Hitchcock buys the rights to a French story and decides to re-set it in San Francisco. Attempts to come up with a workable script initially fail but someone glues a lot of bits and pieces together and comes up with this tedious mess.
It might have worked with a different cast - Jimmy is too old, too stiff, Kim is just too stiff.
Stupid 1950s American prudishness crippled this turkey from the start. Apparently Hitchcock was very conscious of the censor's interest in his films, so much so that even Madeleine's bra could not be shown on the clothesline in Scottie's apartment after he "rescued" her. A scene of him relishing undressing her might have added some kinky veracity to his unexplained desire.
I guess Midge was a friend with benefits, but of course in those days Hitchcock couldn't go there either. Whatever, there's way more chemistry between Midge and Scottie than between Scottie and Madeleine/Judy. Scottie trying to remould Midge as an interim Madeleine might have been interesting.
The stagey backdrops are awful, particularly Midge's apartment at night and the studio-planted Joshua tree by the coast, presumably done to have total control over lighting and sound. Those fifties technicians had no idea their work would be scrutinised in high definition sixty-odd years later, so maybe that's forgivable.
There may be some kind of story potential here, who knows? Hitchcock was over budget, out of time and the whole thing has a whiff of desperation.
I loved "The Lady Vanishes" and "Foreign Correspondent" and remember "Rear Window" very fondly. All three are way, way better than "Vertigo".