these are two very different categories. the rnw is an ampoule (one of the best ampoules I've ever tried) and the isntree is a moisturizer.
they are both good in their own way. it depends on your needs and budget. if you are in for it, then get both of them because they are really good. if you need to be more careful and get only one at a time, I suggest starting with the one that you don't have in your current routine. I hope ny answer makes sense 😅😅