I thought this was a lovely book. Clean and thoughtful.
Full disclosure: I've spent time as an existentialist (Camus said he was not existentialist, but others claim he was) and a nihilist and an absurdist. That's part of the reason I found this book neither shocking nor depressing. The whole middle of the book involves prison and a "why bother" attitude. Instead, the modernist prose was a fresh breath after the musty classics and period fiction I've been reading recently, and the solitude was a relaxing diversion from my busy and loud life.
The Stranger reminded me of Saul Bellow and Raymond Chandler. I love Raymond Chandler. I hope to read this tiny book again one day and see how it strikes me a second time.