I'm more than half way through the seven-volume epic now, and sufficiently engaged to be sure that I will indeed finish it in due course. Sodom and Gomorrah puts homosexuality front and centre; at the very beginning, we discover that the monstrous Baron de Charlus is in fact perpetually on the lookout for attractive men; and throughout the second half of the book the narrator is tormented by the idea that his girlfriend Albertine is having affairs with her girlfriends. Proust is himself a gay but very closeted writer, putting words in the mouth of a heterosexual narrator who observes but is horrified by homosexuality, and for today's reader there is more of the fascination of watching the author's mental train wreck than the idea that we are learning anything.
There is other stuff going on as well. At first I was afraid that we would have yet more bitchy and superficial social events, but we have the interesting compare and contrast between two key relationships - the narrator and Albertine, and Baron de Charlus and the young plebeian musician Morel - which drives the narrative. There are a couple of interesting confrontations with modern technology - the elevator, the motor car, the aeroplane. There are reflections on art and how people respond to it (a discussion continued from earlier works). And the significance of placenames is a major sub-theme of the last third of the book. All quite fascinating, and yet again I feel will reward re-reading in due course.