Palpek posted:

I agree that GPS caches is the least revealing collectible type. But relics and documents are neat. Documents actually tell you a lot about the motivations of various characters and relationships between them, relics have a lot of flavor and some of them contain hidden details when you rotate them. Also collecting all GPS caches will reveal a hidden message at the end that might be a clue for the sequel. Salvage crates on the other hand contain wepon parts and you won't be able to upgrade them if you just avoid them.