I honestly haven't the whole Xerjoff line, hell I don't even remember what I tried, though I remember vanilla in most of them, so much for high quality exotic ingredients. They have decent quality and complexity. Nowhere near Amouage in my humble opinion. Some of Xerjoff packaging is also quite ugly, sure those expensive stone bottles they use are made of lovely stone, but the designs are just...meh, compared to Amouage sophisticated bottles, yeah.
Having said that I obviously chose Amouage and would chose Amouage Dia. Again, I hardly tried Xerjoff, but judging from the little memory, their notes and bottle design, meh.