It depends on what is available and what the AP discount is. AP discounts are offered for select days at set prices. The DVC discount is for 25% off the rack rate but isn't always available. You'll have to do some research into which is a better deal for your dates.
I've found studios are usually better with the AP rate. For example, an OKW studio for October (regular season) is $184 plus tax for the AP rate, rack rate is $315, so 25% off would be $236.
For me in July the 25% discount on a VWL studio was $236. The AP rate was $12 cheaper, but I would have had to check in and out and get new keys. Since we were using the Dining plan for 3 days I was worried it would get screwed up and found it easier to pay $12, keep the same keys and know the DDP was set for the WL portion of our stay.
Keep in mind if you are going to link a cash ressie with a points ressie, then the DVC discount through MS is the way to go. You can link those together so you will not have to move rooms. Reserving an AP discounted room through CRO means there is a very good possibility that you will have to change rooms, or at the very least check in and out on that day it switches.