We own at Aulani, BLT and AKV. We use our Aulani points mainly at Aulani and stay there every other year. If we have some dangling points left over from Aulani that cannot be use in our next Aulani reservation because they will expire then we use those points towards a WDW vacation. Our AKV and BLT points are used for our stays at any
DVC resort of our choice, although we often stay at BLT and stay at AKV at least every other year as we love our home resorts.
Like Kidanifan08 said we purchased roughly half the number of points (rounded up slightly) we needed to stay at Aulani every other year, planning on using those points strictly for Aulani stays in a studio. It isn't because of the cost of the points but because we wanted the 11 month advantage at Aulani.