They pretty much do the same thing. During my first playthrough, I spared him, but in the second, I shot him. Personally, I like the ending where Maurice is spared, because there's more dialogue. But to each their own.
@XxBRIM76xX I shot him because, in the last burner phone, Maurice says that his wife was sent to the auction. In the previous burner phones, he talked about how his life was being ruined, and, in the end, it was. He was kidnapped and most likely tortured. He went insane while with Jordi. It was more of a mercy killing. I was ending his pain.