I found that whole lost Edwardian English world of niceness-and-propriety-at-all-costs to be excruciating. I quickly figured out that's what Forster intended, and warmed to the book. I ended up liking it very much and finding it very moving, even though it describes a world and a set of issues so very different from ours.
Here is a scene from the 1985 movie version of the novel, a very dramatic and very key scene in the novel. Our heroine, Lucy Honeychurch, becomes the unwilling witness to a murder in the Piazza Signoria. Young George Emerson rescues her.
I suppose it's inevitable to find movie versions of stories to be disappointing, but I think the Merchant Ivory team lost the whole thread of the story in the period costumes and magnificent setting.
In the novel, the scene takes place at twilight. Lucy has just bought a set of photo reproductions (significantly all of famous nude paintings considered disreputable by respectable Victorian English opinion). The anonymous man is murdered during a quarrel over money, very much as the movie shows us. Lucy in the movie is very much as I would imagine, but George in the novel is very different from the poised figure in the movie. In the novel, he is very young, and much more visibly lower class (certainly far below Lucy's social station). George in the novel is indeed very gallant as he is in the movie, but much more shaken and anxious. He throws away the photos much more impulsively in the novel, and his tone with Lucy as he tries to explain that something has "happened" to both of them is much more anxious and even desperate. George is just as fresh and uncertain as Lucy is. The whole novel is about the two of them "coming of age," leaving behind the fancies of youth for the much graver matters of adulthood. The murder in the Piazza is the beginning of that process for both of them.
Aesthetics (personified by Florence and Italy) plays a very large and challenging role in the novel. The English tourists and ex-pats are very proud of their erudition and taste in matters of art, and yet Forster describes their living quarters as dark, cramped, and even tasteless. The Reverend Mr. Eager, rector of the English church in Florence (where I attended evensong on my last visit), is a ferocious Pharisee in the novel, a ruthless enforcer of social norms, and frightfully bigoted despite his fluency in Italian. The other cleric, the Reverend Mr. Beebe, is quite a bit more liberal and approachable, but is in the end, just as committed to enforcing social convention as Reverend Eager. Their tastes in art run to very "safe" mediocrities like Alessio Baldovinetti, and others perceived at the time as "safe" like Fra Angelico. Giotto is just tolerated, while Donatello and Michelangelo are unspeakable (precisely because they arouse strong emotions, especially sexual ones).
The Beautiful for them, and for conventional English society, is a retreat, a refuge from the mess (and the demands) of life. Forster makes it clear that all of these people miss the point of Florence and of its art. Art is not supposed to be an escape from life and its demands, but a portal back into them, a way of returning to life with eyes refreshed and opened a little wider. Lucy and George do figure this out on their own. They get to the heart of the matter by trial and error in a way that all of the erudition and pedantry of their fellows completely misses.
The other thing that I found so remarkable about the story is Forster's generosity toward almost all of his characters. Even cads are granted their moments of sympathy and genuine feeling. Lucy's awful supercilious fiance Cecil Vyse acts unexpectedly nobly, and we feel real sympathy for him when Lucy breaks their engagement.
A badly decayed painting of the Nativity by Alessio Baldovinetti in Santissima Annunziata in Florence whose background landscape plays a large role in Forster's novel.
Here is one of my favorite paragraphs in the whole book:
The Piazza Signoria is too stony to be brilliant. It has no grass, no flowers, no frescoes, no glittering walls of marble or comforting patches of ruddy brick. By an odd chance -- unless we believe in a presiding genius of place -- the statues that relieve its severity suggest, not the innocence of childhood nor the glorious bewilderment of youth, but the conscious achievements of maturity. Perseus and Judith, Hercules and Thusnelda, they have done or suffered something, and, though they are immortal, immortality has come to them after experience, not before. Here, not only in the solitude of Nature, might a hero meet a goddess, or a heroine a god.