“I know this much is true” content and length

I picked up “I know this much is true” at a thrift store the other day, and I’m curious to hear what those who’ve read it think.

It’s longer than the books I typically read (my average is around 375 pages), and since I have a hard time DNFing once I start a book, committing to this one feels like a big decision.

For those who have read it—what did you think? How long did it take you to finish? Did it drag, or was the story compelling enough to justify the length?

I also know the book is sad—I’m familiar with the basic premise—but is it so weighed down with misery that reading it feels like a chore? I really disliked A Little Life for this reason. I don’t want to read an excessively long book if it is reminiscent of that level of emotional anguish again.

However I also see reviews praising it very highly, so I don’t want to read an”judge a book by its cover” or by its length, etc.