Although it is fashionable, and generally useless, to call a writer underrated, if I were to do so, James Salter (who passed away in 2015) certainly fits the bill.
Salter saw much critical but not commercial success. He was the kind of writer who was not flashy or ostentatious. His prose is solid and rewarding to read. He crafts sentences of great beauty and strength. He knows how to create characters and move them through time, forming their characteristics with exacting detail. He is a steady, reliable writer who is never, however, boring. Reading his works are rewarding experiences.
His last novel, All That Is, is a bit more loosely constructed than most of his other work. Characters appear, only to disappear, and we wonder if they will return. But they do, even if Salter allows them to wander to 75 pages or more.
So, this novel is an exercise in patience and openness. Give this novel a substantial chance. Read 50 pages and reserve judgement. You’ll be compensated for your persistence.