It's all about the trade power assigned by RCI for your deposit in the case of RCI Weeks. Since trade power is not a published value, you have to rely on word of mouth. If you are buying resale and the current owner happens to have a week deposited with RCI, you could ask for access to the account to verify the numbers before you buy. Until this year, even using that strategy was iffy but now there are actual numbers reported that you can compare with others who have strong traders to be more sure. Even then, trade power can change over time based on the whim of RCI.
With points, there is less of a question of whether what you own can get you where you want to go when you want to be there. Point values vary greatly, though. A 2 bdr in Hawaii can be 108K points. I have two 2 bdr points units that combined only get me 92K. So, for me to go to that Hawaii resort, I would need to trade the equivalent of almost 2.2 of my points timeshares for one in Hawaii.
Dollar for dollar, it is far cheaper for me to exchange for Hawaii using a weeks exchange than it will ever be using a standard points reservation. Since my trade power (so far) will get me the same Hawaii resort for only 1 weeks unit in exchange, that is a better route for me.
However, if my weeks unit did not have the trade power needed to make that trade, at least with points I would have the option of deciding to use 2.2 units worth of points to go where I wanted to go. With weeks, I would just be out of luck.