It's been almost 11 years since I read the book, but my recollection is you're a bit kinder to it than I was. I wrote this in my 2013 self-portrait essay https://medium.com/p/7bdac6f1510e:

"Last night I read 150 pages of a book. Two months ago I would have watched four hours of television. Now in less than 2 months I have read The Sun Also Rises (disappointing — the prose was too bland), Steppenwolf (I love the way Hesse writes), For Whom the Bell Tolls (fucking beautiful narrative prose and, among other things, a tragic but somehow not sad love story) [emphases added]"