AP golf discount is 30% off most times of day (not useable with any other discount and thus, e.g., not useable in late afternoon when you are getting heavily discounted twilight rate). That is 30% off the Disney "Day Guest" rate which is the highest rate (applicable to those coming from off-site who have no other discount).
The DVC discount is now 25% before 10 a.m. and 40% after 10. It is better than the AP discount both those times of day because it is a discount off the Disney "Resort Guest" rate, which is the normal rate for those staying on site and that rate itself is significantly less than the "Day Guest" rate.
In any event, the current DVC discount is worse than it was before. When going and deciding whether to use the DVC discount make sure you first check other discounts. For example, there is usually a 2-round discount being offered to anyone -- you pay for two rounds and get a discount and thus can play twice while you are there and can buy as many 2-round passes as you desire. Right now that 2-round discount is better than doing the before-10 a.m. 25% DVC discount for 2 rounds (but not better than the 40% discount for after 10 rounds).