I don't own at Grandview, but do have both RCI points and weeks elsewhere. If you already have an RCI points account, you can deposit your weeks unit for points for something like $26 (if I remember right). I like having both because it opens up my options to use the non-points one in other exchanges (e.g., SFX), which is a bit harder to do with a points one (I haven't tried to, but it might be possible with some exchanges) because the reservation would already have been handled by one exchange company (RCI) and other exchange companies don't seem to want to deal with that situation. The sole exception seems to be Wyndham, which seems to accept RCI points as part of a PIC for Wyndham points, but the two exchanges are owned by the same company.
If you only plan to use RCI, I agree with the other recommendations to go with points in order to maximize your flexibility. If you're going to use any other system, you might want to look into the pros and cons of it before making a decision. (There's also the issue of needing a guest certificate if you rent your week or give it to someone else; where I own it's simpler and cheaper dealing directly with the resort than going through RCI for one.)