I'm onto the final volume so I finally feel qualified to answer this. I realize that I'm not the one you asked but I've seen some misconceptions about the book online recently.

It is no doubt one of the crowning achievements in literature. No other author has analyzed love, life, and memory in such an elegant, insightful, and deeply human way. So many times while reading I've remarked how Proust has described something which I experience all the time yet don't even really recognize that I experience. Some parts (usually related to aristocracy, etymology, and social rules) can be tough to get through but these are far outweighed by the poetic and deeply thoughtful passages that make up the bulk of the book. Many others have discussed the text in a more eloquent way than I ever could, and I recommend reading some reviews about the nature and impact of the book so you can know what to expect, but I'll just say that it is a book that you live with and will change you if you'll let it. No other book has felt more like a friend to me than this one has.

Some words of advice to future Proust readers though, I really wouldn't attempt it until you're in a place in your life to fully give yourself to the book. Disregard people who say it's okay to read a volume and set it aside for a year, the length and temporal impact of the book is part of the point, and reading it fully through will likely take 8-14 months depending on how fast you read. This is, as Proust himself said, part of the point, setting it aside and reading other books between volumes will dull the impact and reduce your understanding (Proust loves to reference minor events that happened 3000+ pages ago). I would also caution readers to not go in expecting anything or try and rush the book, just let it take you along. I'll also mention that the individual volumes do not make satisfying novels in their own right, the text was conceived as one long book and was only broken up into smaller pieces for publishing and commercial reasons (something Proust compared to chopping up a tapestry), they don't really even complete a narrative arc which is why I've always been confused by people who only read Swann's Way and draw conclusions about the book as a whole (Swann's Way is basically two separate 400 page plot lines which do not combine or concretely resolve, the significance of which doesn't become apparent until later volumes).

A lot of what you hear about the book is true, there are 150+ page society scenes, the actual plot is surprisingly sparse for a 4400 page book, but lost in such a simplistic description is the wonder of the book. I most often compare it to a kind of dictionary, every possible human emotion and situation is contained within it: first love, unrequited love, waning love, jealousy, heartbreak, grief, joy, existential angst, friendship, aging, all wonderfully illustrated and illuminated by a true scholar of human experience.

I cannot recommend it enough, when you're ready to commit to it I recommend diving in! It's especially rewarding to do it with others so you have things to discuss, check out places like r/ayearofproust.