John's done a really great job here, and given me exactly what I was looking for: something that is immediately identifiable as a thriller, but is striking enough to stand out from the pack. It looks modern, but at the same time the colours and font give it a retro 70s vibe. I think that nicely mirrors the neo-noir sensibility of the book.
The font is exactly what I was looking for: big, chunky and no-nonsense. It's Poplar, for the font geeks.