I love WorldMark. I wouldn't take anything RCI Points, but we have owned RCI Points for years now, 17-18 years, and I have seen a serious decline in available resorts, and we have seen an uptick in how many points it takes to get our desired locations, like Wyndham Shearwater. It's cheaper to get it with WorldMark through RCI. And the fees to stay in the Hiltons. I think Shearwater was 150,000 RCI last time I booked a week in March.
WorldMark is the BEST timeshare points product for using in RCI or using in the WorldMark system. I have yet to use it in II for exchanges, so I cannot comment on that.
Better resort locations (even Yellowstone and Estes Park and other locations no other system offers), and the cost to buy is very low and the fees are reasonable. We own 46,000 points, which is enough to get 3-4 two or three bedroom weeks per year, and our cost on a 3 bedroom at Dolphin's Cove in Anaheim is about $1,250. That's it. That is not an exchange.