I have greater respect for James Nachtwey after seeing War Photographer. I was familiar with his work, but I didn't know much about his approach or character. He's one of those "Concerned Photographers" in the same vein as Don McCullin (whom I mention often), Eugene Richards, and many more (including, I suppose, Cornell Capa, who coined the term).
If I had $100 for Nachtwey's Inferno, I think it's definitely worth owning.
Check out an interview with him from a few years ago.