Aesthetics is something you will need decide. I prefer letting the end user decide what to get since you'll be living with the build. If you were to entrust us with your investments...I'd suggest that the XPG is just a marketing gimmick, since they do not connect to a watercooling loop(regardless of what you do. It's just a prefilled ram heatsink with liquid that has nowhere no go.
Functionally speaking, I'd go with the G.Skill.